RBBN Ribbon Communications Inc

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Business

Ribbon Communications Inc. ("Ribbon" or the "Company") is a leading global provider of communications technology to service providers and enterprises. The Company provides a broad range of software and high-performance hardware products, network solutions, and services that enable the secure delivery of data and voice communications, and high-bandwidth networking and connectivity for residential consumers and for small, medium, and large enterprises and industry verticals such as finance, education, government, utilities, and transportation. Ribbon's mission is to create a recognized global technology leader providing cloud-centric solutions that enable the secure exchange of information, with unparalleled scale, performance, and elasticity. The Company is headquartered in Plano, Texas, and has a global presence with research and development, or sales and support locations in over thirty countries around the world.

Basis of Presentation

In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments, consisting only of normal recurring items, necessary for their fair presentation with accounting principles generally accepted in the United States of America ("GAAP") and with the rules and regulations of the U.S. Securities and Exchange Commission ("SEC").

Interim results are not necessarily indicative of results for a full year or any future interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2023, as amended (the "Annual Report"), which was filed with the SEC on February 28, 2024.

Operating Segments

The Company's chief operating decision maker (the "CODM") is its president and chief executive officer. The CODM assesses the Company's performance based on the performance of two separate organizations within Ribbon: the Cloud and Edge segment ("Cloud and Edge") and the IP Optical Networks segment ("IP Optical Networks").

Significant Accounting Policies

The Company's significant accounting policies are disclosed in Note 2 to the Consolidated Financial Statements included in the Annual Report. There were no material changes to the significant accounting policies during the three months ended March 31, 2024.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Ribbon and its wholly-owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation.

Use of Estimates and Judgments

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and judgments relied upon in preparing these condensed consolidated financial statements include revenue recognition for multiple element arrangements, inventory valuations, assumptions used to determine the fair value of stock-based compensation and the Preferred Stock and Warrants, intangible asset and goodwill valuations, including impairments, warranty accruals, legal contingencies and recoverability of Ribbon's net deferred tax assets and the related valuation allowances. Ribbon regularly assesses these estimates and records changes in estimates in the period in which they become known. Ribbon bases its

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estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates.

Transfers of Financial Assets

The Company's IP Optical Networks segment maintains customer receivables factoring agreements with a number of financial institutions. Under the terms of these agreements, the Company may transfer receivables to the financial institutions, on a non-recourse basis, provided that the financial institutions approve the receivables in advance. The Company maintains credit insurance policies from major insurance providers or obtains letters of credit from the customers for a majority of its factored trade receivables. The Company accounts for the factoring of its financial assets as a sale of the assets and records the factoring fees, when incurred, as a component of interest expense in the condensed consolidated statements of operations, and the proceeds from the sales of receivables are included in cash from operating activities in the condensed consolidated statements of cash flows.

Factoring of accounts receivable and associated fees for the three months ended March 31, 2024 and 2023 were as follows (in thousands):

			Three months ended
			March 31, 2024						March 31, 2023
Accounts receivable sold			20,992						21,061
Less factoring fees			(391)						(455)
Net cash proceeds			20,601						20,606

Going Concern Assessment and Management Plans

The accompanying condensed consolidated financial statements are prepared in accordance with GAAP applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business.

The Company's 2020 Credit Facility (as defined in Note 9) requires quarterly payments of $10.0 million each in the second, third and fourth quarters of 2024, with the remaining balance of $200.4 million due on March 3, 2025. The Company does not have sufficient cash on hand or available liquidity to repay the $200.4 million due on March 3, 2025. In response to these conditions, management's plans include refinancing the 2020 Credit Facility. The Company has entered into a binding commitment letter to refinance the 2020 Credit Facility. See Note 20 - Subsequent Event. The refinance contemplated by the binding commitment letter is expected to close no later than June 30, 2024. However, because the credit facility contemplated by the commitment letter has not yet been finalized, it cannot be deemed to be within the Company's control. As a result, such plans cannot be deemed probable and do not alleviate the substantial doubt raised about the Company's ability to continue as a going concern.

The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

Recent Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board (the "FASB") issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”), which increases the disclosure requirements around rate reconciliation information and certain types of income taxes companies are required to pay. ASU 2023-09 will be effective for the Company beginning in 2025, with early adoption permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which improves reportable segment disclosure requirements, including enhancement of the

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disclosures of significant segment expenses and interim disclosure requirements, to enable investors to better understand an entity's overall performance and assess potential future cash flows. ASU 2023-07 will be effective for the Company annually beginning in 2024 and on an interim basis beginning in 2025, with early adoption permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures.

In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC's disclosure Update and Simplification Initiative (“ASU 2023-06”), which amends the disclosure or presentation requirements related to various subtopics in the FASB Accounting Standards Codification. This ASU was issued in response to, and to align GAAP with, the SEC's August 2018 final rule that updates and simplifies disclosure requirements. The effective date for the Company for each amendment will be the date on which the SEC's removal of that related disclosure requirement becomes effective, with early adoption prohibited. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures.

On February 1, 2023, the FASB staff noted that they believe that the Pillar 2 tax, established by the OECD and intended to apply for tax years beginning in 2024, would be an alternative minimum tax and therefore deferred tax assets would not need to be recognized related to this parallel taxing system. On February 2, 2023, the OECD issued administrative guidance providing transition and safe harbor rules around the implementation of the Pillar 2 global minimum tax. Under an additional transitional safe harbor released July 17, 2023, the undertaxed profits rule top-up tax will not be applied by any constituent entity's jurisdiction of residence with respect to income earned by a company's ultimate parent entity in its jurisdiction of residence, if the ultimate parent entity's jurisdiction has a corporate tax rate of at least 20%. This transition safe harbor will apply to fiscal years beginning on or before December 31, 2025 and ending before December 31, 2026. The Company is closely monitoring developments and evaluating the impacts these new rules will have on its tax rate, including eligibility to qualify for these safe harbor rules. Based upon preliminary calculations for calendar year 2024, the Company anticipates that it will meet the safe harbors in most jurisdictions, and any remaining top-up tax should be immaterial.

Basic earnings (loss) per share is computed by dividing net income (loss) by the weighted average number of shares outstanding during the period. For periods in which the Company reports net income, diluted net earnings per share is determined by using the weighted average number of common and dilutive common equivalent shares outstanding during the period, unless the effect is antidilutive.

The shares used to compute loss per share were as follows (in thousands):

			Three months ended
			March 31, 2024						March 31, 2023
Weighted average shares outstanding - basic			172,428						168,541
Potential dilutive common shares			—						—
Weighted average shares outstanding - diluted			172,428						168,541

Options to purchase the Company's common stock and unvested restricted and performance-based stock units aggregating 12.1 million and 11.9 million shares were excluded from the computation of diluted loss per share for the three months ended March 31, 2024 and 2023, respectively, because their effect would have been antidilutive.

On March 28, 2023, the Company issued 55,000 shares of newly designated Series A Preferred Stock (the "Preferred Stock") to investors in a private placement offering at a price of $970 per share, along with 4.9 million warrants (the "Warrants") to purchase shares of the Company's common stock, par value $0.0001 per share (the "Private Placement"), at the exercise price of $3.77 per share. The proceeds from the Private Placement were approximately $53.4 million, including approximately $10 million from existing related party stockholders (See Note 11).

As of March 31, 2024, the potential number of dilutive shares from the Warrants totaled 4.9 million shares. However, there

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was no impact on weighted average shares outstanding from these Warrants for the three months ended March 31, 2024 as the average share price of the Company's common stock was below the exercise price of $3.77 per share and their effect would have been antidilutive. For the three months ended March 31, 2023, the potential effect from the Warrants on weighted average shares outstanding for the calculation of diluted earnings (loss) per share was de minimis.

Dividends payable on the Preferred Stock are not an adjustment to net income (loss) used for the calculation of diluted earnings (loss) per share as these dividends are included in the fair value adjustment of the Preferred Stock which is reflected in Other (expense) income, net.

Inventory at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):

			March 31, 2024						December 31, 2023
On-hand final assemblies and finished goods inventories			$	98,290					$	93,077
Deferred cost of goods sold			1,927						3,269
			100,217						96,346
Less noncurrent portion (included in Other assets)			(19,459)						(18,825)
Current portion			$	80,758					$	77,521

The Company's intangible assets at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):

March 31, 2024			Weighted average amortization period (years)						Cost						Accumulated amortization						Net carrying value
Developed technology			7.84						$	340,380					$	245,163					$	95,217
Customer relationships			11.86						268,140						141,423						126,717
Trade names			3.88						5,000						4,927						73
Software licenses			3.00						5,486						2,613						2,873
			9.50						$	619,006					$	394,126					$	224,880

December 31, 2023			Weighted average amortization period (years)						Cost						Accumulated amortization						Net carrying value
Developed technology			7.84						$	340,380					$	239,066					$	101,314
Customer relationships			11.86						268,140						134,743						133,397
Trade names			3.88						5,000						4,901						99
Software licenses			3.00						5,436						2,159						3,277
			9.51						$	618,956					$	380,869					$	238,087

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Estimated future amortization expense for the Company's intangible assets at March 31, 2024 was as follows (in thousands):

Years ending December 31,
Remainder of 2024			$	37,557
2025			44,105
2026			39,056
2027			33,939
2028			23,400
2029			18,379
Thereafter			28,444
			$	224,880

There were no changes to the carrying value of the Company's goodwill in the three months ended March 31, 2024 and 2023. The components of goodwill at both March 31, 2024 and 2023 were as follows (in thousands):

			Cloud and Edge						IP Optical Networks						Total
Goodwill			$	392,302					$	191,996					$	584,298
Accumulated impairment losses			(167,406)						(116,000)						(283,406)
			$	224,896					$	75,996					$	300,892

The carrying amounts of the Company's cash equivalents, accounts receivable, accounts payable and borrowings under a revolving credit facility in the condensed consolidated balance sheets approximates fair value due to the immediate or short-term nature of these financial instruments. Ribbon's term debt balance as of March 31, 2024 and December 31, 2023 of $230.4 million and $235.4 million, respectively, had a fair value of approximately $231.5 million and $235.1 million, respectively. Our Preferred Stock and Warrants liabilities had a combined fair value of $62.1 million as of March 31, 2024, including cumulative dividends on the Preferred Stock of $5.3 million.

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The three-tier fair value hierarchy is based on the level of independent, objective evidence surrounding the inputs used to measure fair value. A financial instrument's categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The fair value hierarchy is as follows:

Level 1. Level 1 applies to assets or liabilities for which there are quoted prices in active markets for identical assets or liabilities. The Company had no assets or liabilities fair valued using Level 1 input at March 31, 2024 or December 31, 2023.

Level 2. Level 2 applies to assets or liabilities for which there are inputs that are directly or indirectly observable in the marketplace, such as quoted prices for similar assets or liabilities in active markets or quoted prices for identical assets or liabilities in markets with insufficient volume or infrequent transactions (less active markets). At December 31, 2023, the Company determined the fair value of its defined benefit plans' assets using Level 2 input. There were no significant changes to the Company's defined benefit plans' assets during the three months ended March 31, 2024 that required the calculation of their fair value as of March 31, 2024.

Level 3. Level 3 applies to assets or liabilities for which there are unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of the assets or liabilities. At March 31, 2024 and December 31, 2023, the fair value of the Company's Preferred Stock and Warrants were determined using Level 3 input.

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Accrued expenses at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):

			March 31, 2024						December 31, 2023
Employee compensation and related costs			$	29,505					$	33,682
Professional fees			19,148						19,702
Taxes payable			3,653						8,383
Other			32,185						29,920
			$	84,491					$	91,687

The changes in the Company's accrual balance in the three months ended March 31, 2024 were as follows (in thousands):

Balance at January 1, 2024			$	12,243
Current period provisions			1,347
Settlements			(1,334)
Balance at March 31, 2024			$	12,256

The Company recorded restructuring and related expense aggregating $3.1 million and $6.9 million in the three months ended March 31, 2024 and 2023, respectively. Restructuring and related expense includes restructuring expense (primarily severance and related costs), estimated future variable lease costs for vacated properties with no intent or ability of sublease, and accelerated rent amortization expense.

For restructuring events that involve lease assets and liabilities, the Company applies lease reassessment and modification guidance and evaluates the right-of-use assets for potential impairment. If the Company plans to exit all or distinct portions of a facility and does not have the ability or intent to sublease, the Company will accelerate the amortization of each of those lease components through the vacate date. The accelerated amortization is recorded as a component of Restructuring and related expense in the Company's condensed consolidated statements of operations. Related variable lease expenses will continue to be expensed as incurred through the vacate date, at which time the Company will reassess the liability balance to ensure it appropriately reflects the remaining liability associated with the premises and record a liability for the estimated future variable lease costs.

Accelerated amortization of lease assets is recognized from the date that the Company commences the plan to fully or partially vacate a facility, for which there is no intent or ability to enter into a sublease, through the final vacate date. Accelerated amortization of lease assets that are included as a component of restructuring and related expense are excluded from the restructuring accrual activity tables below, as the liability for lease payments for these facilities is included as a component of current and noncurrent Operating lease liabilities in the Company's condensed consolidated balance sheets at March 31, 2024 and December 31, 2023 (see Note 16). The Company may incur additional future expense if it is unable to sublease other locations included in the Company's facilities consolidation initiatives.

Restructuring and related expense for the three months ended March 31, 2024 and 2023 was comprised of the following (in thousands):

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			Three months ended
			March 31, 2024						March 31, 2023
Severance and related costs			$	1,616					$	5,708
Variable and other facilities-related costs			1,449						$	1,006
Accelerated amortization of lease assets due to cease-use			—						$	223
			$	3,065					$	6,937

2023 Restructuring Plan

On February 22, 2023, the Company's Board of Directors approved a strategic restructuring program (the "2023 Restructuring Plan") to streamline the Company's operations in order to support the Company's investment in critical growth areas. The 2023 Restructuring Plan includes, among other things, charges related to a workforce reduction. Any potential positions eliminated in countries outside the United States are subject to local law and consultation requirements.

In connection with the 2023 Restructuring Plan, the Company recorded restructuring and related expense of $1.6 million and $5.7 million in the three months ended March 31, 2024 and 2023, respectively, consisting entirely of severance related costs. A summary of the 2023 Restructuring Plan accrual activity for the three months ended March 31, 2024 is as follows (in thousands):

			Balance at January 1, 2024						Initiatives charged to expense												Cash payments						Net transfer to operating lease accounts						Balance at March 31, 2024
Severance			$	671					$	1,616											$	(1,284)					$	—					$	1,003

2022 Restructuring Plan

On February 14, 2022, the Company's Board of Directors approved a strategic restructuring program (the "2022 Restructuring Plan") to streamline the Company's operations in order to support the Company's investment in critical growth areas. The 2022 Restructuring Plan includes, among other things, charges related to a consolidation of facilities and a workforce reduction. Any positions eliminated in countries outside the United States are subject to local law and consultation requirements.

The Company recorded restructuring and related expense of $1.4 million and $1.2 million in the three months ended March 31, 2024 and 2023, respectively, in connection with the 2022 Restructuring Plan. The amount for the three months ended March 31, 2024 was comprised of $1.4 million for facilities-related costs. The amount for the three months ended March 31, 2023 was comprised of $1.0 million for variable and other facilities-related costs and $0.2 million for accelerated amortization of lease assets no longer being used with no ability or intent to sublease. A summary of the 2022 Restructuring Plan accrual activity for the three months ended March 31, 2024 is as follows (in thousands):

			Balance at January 1, 2024						Initiatives charged to expense																		Cash payments												Balance at March 31, 2024
Variable and other facilities-related costs			$	468					1,449																		(1,495)												$	422

Balance Sheet Classification

The current portions of accrued restructuring were $1.4 million and $1.1 million at March 31, 2024 and December 31, 2023, respectively, and are included as components of Accrued expenses in the condensed consolidated balance sheets. The long-term portions of accrued restructuring are included as components of Other long-term liabilities in the condensed consolidated balance sheets. The long-term portions of accrued restructuring were $1.0 million and $1.1 million at March 31, 2024 and December 31, 2023, respectively.

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2020 Credit Facility

On March 3, 2020, the Company entered into a Senior Secured Credit Facilities Credit Agreement (as amended, the "2020 Credit Facility"), by and among the Company, as a guarantor, Ribbon Communications Operating Company, Inc., as the borrower ("Borrower"), Citizens Bank, N.A. ("Citizens"), Santander Bank, N.A., and others as lenders ("Lenders"). The proceeds from the Credit Agreement were used, in part, to pay off in full all obligations of the Company under the 2019 Credit Facility.

The 2020 Credit Facility originally provided for $500 million of commitments from the Lenders to the Borrower, comprised of $400 million in term loans (the "2020 Term Loan Facility") and a $100 million facility available for revolving loans (the "2020 Revolving Credit Facility"). Under the 2020 Revolving Credit Facility, a $30 million sublimit was originally available for letters of credit and a $20 million sublimit remains available for swingline loans.

The indebtedness and other obligations under the 2020 Credit Facility are unconditionally guaranteed on a senior secured basis by the Company, Edgewater Networks, Inc., a wholly-owned subsidiary of the Company, and GENBAND Inc., a wholly-owned subsidiary of the Company (together, the "Guarantors"). The 2020 Credit Facility is secured by first-priority liens on substantially all of the assets of the Borrower and the Guarantors, including substantially all of the assets of the Company.

The 2020 Credit Facility requires compliance with certain financial covenants, including a minimum Consolidated Fixed Charge Coverage Ratio and a maximum Consolidated Net Leverage Ratio (each as defined in the 2020 Credit Facility, and each tested on a quarterly basis).

On August 18, 2020, the Company entered into the First Amendment to the 2020 Credit Facility in which $75 million of the 2020 Term Loan Facility was assigned from Citizens to a new lender and designated as the Term B Loan. The remaining $325 million of the 2020 Term Loan Facility was deemed the Term A Loan.

The Term A Loan and the 2020 Revolving Credit Facility mature in March 2025 and originally bore interest at the Borrower's option at either the LIBOR rate plus a margin ranging from 1.50% to 3.50% per year, or the base rate plus 0.50%, or the prime rate plus a margin ranging from 0.50% to 2.50% per year (the "Applicable Margin"). The Applicable Margin varied depending on the Company's Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility).

The Term B Loan was scheduled to mature in March 2026 and bore interest, at the Borrower's option, at either the LIBOR rate plus a margin of 7.50% per year, or the base rate (the highest of the Federal Funds Effective Rate (as defined in the First Amendment) plus 0.50%, or the prime rate.

On December 1, 2020, the Company entered into the Second Amendment to the 2020 Credit Facility to obtain consent for an equity exchange with AVCT in connection with the sale of our Kandy Communications business, as well as to amend certain other provisions of the 2020 Credit Facility.

On March 3, 2021, the Company entered into the Third Amendment to the 2020 Credit Facility which provided for an incremental term loan facility in the principal amount of $74.6 million, the proceeds of which were used to consummate an open market purchase of all outstanding amounts under the Term B Loan, resulting in the assignment and immediate cancellation of the Term B Loan, such that the outstanding amount under the Term A Loan and incremental term loan facility were combined and held by the Lenders (the "2020 Term Loan") with the same terms as the Term A Loan. The Company wrote off $2.5 million of capitalized debt issuance costs in connection with the Third Amendment.

On March 10, 2022, the Company entered into the Fourth Amendment to the 2020 Credit Facility to increase the Maximum Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility) and in conjunction the Company made a $15.0 million prepayment that was applied to the final payment due on the maturity date.

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On June 30, 2022, the Company entered into the Fifth Amendment to the 2020 Credit Facility (the "Fifth Amendment") to increase the Maximum Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility) for 2022, with the fourth quarter of 2022 increased to 4.75:1.00, the first and second quarters of 2023 declining to 3.25:1.00, and in all subsequent quarters the ratio was to be fixed at 3.00:1.00. Also, the Fifth Amendment reduced the minimum Consolidated Fixed Charge Coverage Ratio (as defined in the 2020 Credit Facility) in 2022, with the fourth quarter of 2022 reduced to 1.10:1.00 and in all subsequent quarters the ratio was to be fixed at 1.25:1.00. In addition, the Fifth Amendment increased the maximum rate at which loans were to bear interest if the Company's Consolidated Net Leverage Ratio for any quarter was greater than 4.50:1.00. Specifically, loans incurred would bear interest, at the Borrower’s option, at either LIBOR plus a margin ranging from 1.50% to 4.50% per year, or the base rate plus 0.50%, or the prime rate plus a margin ranging from 0.50% to 3.50% per year. The Fifth Amendment also allows the Company to incur junior secured or unsecured debt in an amount no less than $50 million, subject to certain conditions, including the requirement that 50% of the aggregate amount of such incurred debt (net of certain costs, fees and other amounts) must be applied to prepay the 2020 Credit Facility, and compliance with certain leverage ratio-based covenant exceptions. In connection with the Fifth Amendment, the Company made a $10.0 million voluntary prepayment that was applied to the final payment due on the maturity date. Subsequent to the Fifth Amendment, the Company is required to make quarterly principal payments on the 2020 Term Loan aggregating approximately $5.0 million per quarter through March 31, 2024 and $10.0 million in each of the three quarters thereafter, with the remaining and final payment due on the maturity date in March 2025.

On March 24, 2023, the Company entered into the Sixth Amendment to the 2020 Credit Facility (the “Sixth Amendment”) effective March 30, 2023. The Sixth Amendment, among other things, increased the Maximum Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility), with the first, second and third quarters of 2023 increasing to 4.50:1.00. In the fourth quarter of 2023 and the first quarter of 2024, the Maximum Consolidated Net Leverage Ratio declines to 4.25:1.00 and 4.00:1.00, respectively. In all subsequent quarters, the Maximum Consolidated Senior Net Leverage Ratio will be fixed at 3.00:1.00 and the Maximum Consolidated Net Leverage Ratio will be fixed at 4.00:1.00. Also, the Sixth Amendment reduced the minimum Consolidated Fixed Charge Coverage Ratio (as defined in the 2020 Credit Facility) to 1.10:1.00 through the first quarter of 2024 and in all subsequent quarters the ratio will be fixed at 1.25:1.00. The Sixth Amendment reduced the maximum borrowings allowed under the 2020 Revolving Credit Facility from $100 million to $75 million and the sublimit available for letters of credit was reduced from $30 million to $20 million. In addition, the Sixth Amendment replaced LIBOR with the Secured Overnight Financing Rate ("SOFR") as the alternative rate that may be used by the Company for calculating interest owed under the 2020 Credit Facility with the margin now fixed at 4.5%. In conjunction with the Sixth Amendment, the Company made a $75 million prepayment that was applied to the final payment due upon maturity in March 2025 of approximately $200.4 million. The $75 million prepayment was almost entirely funded with the net proceeds from the Private Placement and the sales of our interest rate swap. Debt issuance costs associated with the Sixth Amendment totaled $1.7 million and are being amortized on a straight-line basis over the remaining life of the 2020 Credit Facility to Interest expense, net.

The Company's interest rates under the 2020 Term Loan for the three months ended March 31, 2023 benefited from a hedge instrument that was in place, specifically a fixed rate swap, which was sold in March 2023 (see Note 10). As a result of the fixed rate swap sold in March 2023, the ongoing interest rate is based upon U.S. dollar SOFR plus a fixed margin of 4.5%. The Company was in compliance with all covenants of the 2020 Credit Facility at both March 31, 2024 and December 31, 2023, including the current Consolidated Net Leverage Ratio calculation that considers the Company's debt to include Preferred Stock.

The Company had the following outstanding borrowings, unamortized debt issuance costs, letters of credit, interest rates, and remaining borrowing capacity under the 2020 Credit Facility as of March 31, 2024 and December 31, 2023:

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			March 31, 2024						December 31, 2023
Current portion of Term Debt			$	228,168					$	35,102
Long-term Debt, net of Current:
Long-term Debt, net of Current (Face Amount)			$	—					$	200,293
Unamortized Debt Issuance Costs - Contra-Liability			—						(2,811)
Long-term Debt, net of Current			$	—					$	197,482
Total Face Amount of Borrowings			$	230,381					$	235,395
Unamortized Debt Issuance Costs:
Other Assets			$	439					$	557
Current Portion of Term Debt - Contra Liability			2,213						—
Long-Term Debt - Contra Liability			—						2,811
Total Unamortized Debt Issuance Costs			$	2,652					$	3,368
Letters of Credit Outstanding			$	2,711					$	2,711
Remaining Borrowing Capacity			$	72,289					$	72,289
Average Interest Rates:
Term Loan			9.9		%				10.0		%
Letters of Credit			4.5		%				4.5		%

The Company's debt maturities as of March 31, 2024 were as follows:

Years ending December 31,
Remainder of 2024			$	30,087
2025			200,294
			$	230,381

Letters of Credit and Other Guarantees

The Company is exposed to financial market risk related to foreign currency fluctuations and changes in interest rates. These exposures are actively monitored by management. To manage the volatility related to the exposure to changes in interest rates, the Company may enter into derivative financial instruments. Management's objective has been to reduce, where it is deemed appropriate to do so, fluctuations in earnings and cash flows associated with changes in interest rates. Ribbon's policies and practices are to use derivative financial instruments only to the extent necessary to manage exposures. Ribbon does not hold or issue derivative financial instruments for trading or speculative purposes.

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The Company records derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a specific risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Derivatives may also be designated as hedges of the foreign currency exposure of a net investment in a foreign operation. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge, or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk even though hedge accounting does not apply or the Company elects not to apply hedge accounting.

Cash Flow Hedge of Interest Rate Risk

The 2020 Term Loan Facility had outstanding balances of $230.4 million and $235.4 million at March 31, 2024 and December 31, 2023, respectively. The 2020 Revolving Credit Facility was undrawn at March 31, 2024 and December 31, 2023. Borrowings under the 2020 Credit Facility have variable interest rates based on LIBOR or SOFR (see Note 9). As a result of exposure to interest rate movements, during March 2020, the Company entered into an interest rate swap arrangement, which effectively converted its $400 million term loan with its variable interest rate based upon one-month LIBOR to an aggregate fixed rate of 0.904%, plus a leverage-based margin as defined in the 2020 Credit Facility.

On July 22, 2022, the Company sold $30 million of the notional amount of its interest rate swap back to its counterparty for $1.5 million, reducing the notional amount of this swap to $370 million. On August 16, 2022 the Company sold another $30 million of the notional amount of its interest rate swap back to its counterparty for $1.6 million, reducing the notional amount to $340 million, which approximated the current level of our term loan debt then outstanding. The gain in accumulated other comprehensive (loss) income related to the $60 million notional amount sold of $3.1 million is being released into earnings on a straight line basis over the remaining term of the 2020 Credit Facility as a decrease to interest expense, the amortization of which totaled $0.2 million and $0.3 million for the three months ended March 31, 2024 and 2023, respectively.

On March 24, 2023, the Company received $9.4 million, consisting of $0.4 million of interest and $9.0 million for the sale of $170 million of its $340 million notional amount interest rate swap back to its counterparty, reducing the notional amount to $170 million. On March 27, 2023, the Company received $9.8 million, consisting of $0.4 million of interest and $9.4 million for the sale of the remaining $170 million of its interest rate swap back to its counterparty. The portion of the gain in accumulated other comprehensive (loss) income related to the term loan debt prepaid on the date of the final sale of our swap totaled $7.3 million and was released into earnings immediately as Other expense, net. The portion of the gain in accumulated other comprehensive (loss) income related to our remaining term loan debt balance was $12.0 million and is being released into earnings on a straight line basis over the remaining term of the 2020 Credit Facility as a decrease to interest expense, the amortization of which totaled $1.6 million for the three months ended March 31, 2024.

The Company’s objectives in using interest rate derivatives have been to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company has used an interest rate swap as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the related agreements without exchange of the underlying notional amount.

The effective portion of changes in the fair value of designated derivatives that qualify as cash flow hedges is recorded in accumulated other comprehensive income in the condensed consolidated balance sheet and is subsequently reclassified into earnings in the period that the hedged forecasted transactions affect earnings. During the three months ended March 31, 2023, such a derivative was used to hedge the variable cash flows associated with the outstanding borrowings under the 2020 Credit Facility and the Company has accounted for this derivative as an effective hedge until the final portion of the swap was sold on March 27, 2023. Any ineffective portion of the change in the fair value of the derivative was recognized directly in earnings.

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Amounts reported in accumulated other comprehensive income related to the Company's derivative are reclassified to interest expense as interest is accrued on the Company’s variable-rate debt. The impact of the Company’s derivative financial instrument on its condensed consolidated statements of comprehensive (loss) income for the three months ended March 31, 2024 and 2023 was as follows, net of tax (in thousands):

			Three months ended
			March 31, 2024						March 31, 2023
Gain (loss) recognized in other comprehensive income (loss) on swap, net of tax			$	—					$	(2,715)
Amount reclassified from accumulated other comprehensive income to other expense, net upon sale of swap, net of tax			—						(5,099)
Amount reclassified from accumulated other comprehensive income to interest expense			(1,321)						(3,185)
Unrealized gain (loss) on interest rate swap, net of reclassifications and amortization			$	(1,321)					$	(10,999)

On March 28, 2023, the Company issued 55,000 shares of Preferred Stock to investors in the Private Placement at a price of $970 per share, along with 4,858,090 Warrants with an exercise price of $3.77 per share.

The Company accounts for the Preferred Stock and Warrants as liability-classified instruments based on an assessment of their specific terms in accordance with ASC Topic 480, Distinguishing Liabilities from Equity. The fair value option was elected for the Preferred Stock, as the Company considers fair value to best reflect its expected future economic value. These liabilities are remeasured to fair value at each reporting date using the same valuation methodology applied upon issuance using current input assumptions.

The value of the Preferred Stock is calculated using the Black-Derman-Toy (BDT) stochastic yield lattice model to capture the optimal timing of repayment, increasing dividend rate and other features and the value of the Warrants is calculated using the Black-Scholes Pricing Model.

Changes in the fair value of the Preferred Stock and Warrants are reported as Other expense, net in the Company's condensed consolidated statements of operations.

The Company determined the fair value of the Preferred Stock and Warrants using Level 3 input. The key assumptions into the models utilized were as follows as of March 31, 2024:

			Preferred Stock (BDT)
Face value per share			$1,000
Interest payments per year			4
Dividend rate - year 1 (paid in-kind)			9.25%
Dividend rate - year 2 (paid in-kind or in cash at the Company's choice)			9.75%
Dividend rate - thereafter (paid in cash)			12.00%
Yield volatility			25.0%
Time to maturity (in years)			1.5

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			Warrants (Black-Scholes)
Stock price			$3.20
Strike price			$3.77
Risk-free rate			4.35%
Volatility			59.2%
Dividend yield			0.0%
Time to expiration (years)			3.0

The changes in the Company's Preferred Stock and Warrant liabilities the three months ended March 31, 2024 were as follows (in thousands):

			Preferred stock liability
Balance at January 1, 2024			$	53,337
Payable in-kind dividends			1,355
Fair value change			1,512
Balance at March 31, 2024			$	56,204

			Warrant liability
Balance at January 1, 2024			$	5,295
Fair value change			632
Balance at March 31, 2024			$	5,927

The Preferred Stock is subordinate to Company indebtedness and senior to the Company’s common stock or other equity. Holders of the Preferred Stock are entitled to cumulative dividends that accrue quarterly through the September 30, 2025 maturity date. Dividends are payable in-kind during the first year at a rate of 9.25%. At the Company’s option, the dividends are payable in-kind or in cash during the second year at a rate of 9.75%. Dividends thereafter are payable in cash at a rate of 12.00%. The proceeds from the Preferred Stock issuance were approximately $53.4 million, including $10.0 million from existing related party stockholders. Offering costs paid by the Company of approximately $3.5 million were recorded in Other expense, net in the year ended December 31, 2023. The net proceeds from the Private Placement were used for the repayment of debt. The Preferred Stock is redeemable on or after the first and second anniversaries of the closing date at a rate of 103% and 102%, respectively.

The Warrants, which expire March 30, 2027, are immediately exercisable and upon an event such as a merger, consolidation, asset sale or similar change of control, may be exercised and the holders may vote the underlying shares of common stock. In connection with the Private Placement, the Company provided the investors with certain registration rights relating to the Preferred Stock, the Warrants and the shares of the Company’s common stock underlying the Warrants, that required the Company to file a registration statement on Form S-3 with the SEC within 30 days following the closing date of the Private Placement. The registration requirement was completed on May 19, 2023.

The Company derives revenue from two primary sources: products and services. Product revenue includes the Company's hardware and software that function together to deliver the products' essential functionality. Software and hardware are also sold on a standalone basis. Services include customer support (software updates, upgrades and technical support), consulting, design services, installation services and training. Generally, contracts with customers contain multiple performance obligations, consisting of products and services. For these contracts, the Company accounts for individual performance

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obligations separately if they are considered distinct.

When an arrangement contains more than one performance obligation, the Company will allocate the transaction price to each performance obligation on a relative standalone selling price basis. The Company utilizes the observable price of goods and services when they are sold separately to similar customers in order to estimate standalone selling price.

The Company's software licenses typically provide a perpetual right to use the Company's software. The Company also sells term-based software licenses that expire and Software-as-a-Service ("SaaS")-based software which are referred to as subscription arrangements. The Company does not customize its software nor are installation services required, as the customer has a right to utilize internal resources or a third-party service company. The software and hardware are delivered before related services are provided and are functional without professional services or customer support. The Company has concluded that its software licenses are functional intellectual property that are distinct, as the user can benefit from the software on its own. Product revenue is typically recognized upon transfer of control or when the software is made available for download, as this is the point the user of the software can direct the use of, and obtain substantially all of the remaining benefits from, the functional intellectual property. The Company begins to recognize software revenue related to the renewal of subscription software licenses at the start of the subscription period.

The Company offers warranties on its products. Certain of the Company's warranties are considered to be assurance-type in nature, ensuring the product is functioning as intended. Assurance-type warranties do not represent separate performance obligations. The Company also sells separately-priced maintenance service contracts which qualify as service-type warranties and represent separate performance obligations. The Company does not allow and has no history of accepting product returns.

Services revenue includes revenue from customer support and other professional services. Customer support includes software updates on a when-and-if-available basis, telephone support, integrated web-based support and bug fixes or patches. The Company sells its customer support contracts at a percentage of list or net product price. Customer support revenue is recognized ratably over the term of the customer support agreement, which is typically one year.

The Company's professional services include consulting, technical support, resident engineer services, design services and installation services. Because control transfers over time, revenue is recognized based on progress toward completion of the performance obligation. The method to measure progress toward completion requires judgment and is based on the nature of the products or services to be provided. The Company generally uses the input method to measure progress for its contracts because it believes such method best depicts the transfer of assets to the customer, which occurs as the Company incurs costs for the contracts. However, in some instances, the Company uses the output method because it best depicts the transfer of asset to the customer. Under the cost-to-cost measure of progress, the progress toward completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. When the measure of progress is based upon expended labor, progress toward completion is measured as the ratio of labor time expended to date versus the total estimated labor time required to complete the performance obligation. Revenue is recorded proportionally as costs are incurred or as labor is expended. Costs to fulfill these obligations include internal labor as well as subcontractor costs.

Customer training includes courses offered by the Company. The related revenue is typically recognized as the training services are performed.

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The Company's typical performance obligations include the following:

Performance Obligation

When Performance Obligation is Typically Satisfied

When Payment is Typically Due

Software and Product Revenue

Software licenses (perpetual or term)

Upon transfer of control; typically, when made available for download (point in time)

Generally, within 30 days of invoicing except for term licenses, which may be paid for over time

Software licenses (subscription)

Upon activation of hosted site (over time)

Generally, within 30 days of invoicing

Hardware

When control of the hardware passes to the customer; typically, upon delivery (point in time)

Generally, within 30 days of invoicing

Software upgrades

Upon transfer of control; typically, when made available for download (point in time)

Generally, within 30 days of invoicing

Customer Support Revenue

Customer support

Ratably over the course of the support contract (over time)

Generally, within 30 days of invoicing

Professional Services

Other professional services (excluding training services)

As work is performed (over time)

Generally, within 30 days of invoicing (upon completion of services)

Training

When the class is taught (point in time)

Generally, within 30 days of services being performed

Significant Judgments

The Company's contracts with customers often include promises to transfer multiple products and services to the customer. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment.

Judgment is required to determine the standalone selling price ("SSP") for each distinct performance obligation. The Company typically has more than one SSP for individual products and services due to the stratification of those products and services by customers and circumstances. In these instances, the Company may use information such as the size of the customer and geographic region in determining the SSP.

Deferred Revenue

Deferred revenue is a contract liability representing amounts collected from or invoiced to customers in excess of revenue recognized. This results primarily from the billing of annual customer support agreements where the revenue is recognized over the term of the agreement. The value of deferred revenue will increase or decrease based on the timing of recognition of revenue.

Disaggregation of Revenue

The Company disaggregates its revenue from contracts with customers based on the nature of the products and services and the geographic regions in which each customer is domiciled. The Company's revenue for the three months ended March 31, 2024 and 2023 was disaggregated as follows:

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Three months ended March 31, 2024			Product revenue						Service revenue (maintenance)						Service revenue (professional services)						Total revenue
United States			$	26,607					$	32,847					$	11,660					$	71,114
Europe, Middle East and Africa			41,689						17,696						7,698						67,083
Asia Pacific			16,633						10,241						2,927						29,801
Other			2,681						7,597						1,388						11,666
			$	87,610					$	68,381					$	23,673					$	179,664

Three months ended March 31, 2023			Product revenue						Service revenue (maintenance)						Service revenue (professional services)						Total revenue
United States			$	38,067					$	33,073					$	10,853					$	81,993
Europe, Middle East and Africa			27,435						20,127						6,575						54,137
Asia Pacific			25,615						9,372						3,144						38,131
Other			2,201						8,016						1,681						11,898
			$	93,318					$	70,588					$	22,253					$	186,159

The Company's product revenue from indirect sales through its channel partner program and from its direct sales program for the three months ended March 31, 2024 and 2023 was as follows (in thousands):

			Three months ended
			March 31, 2024						March 31, 2023
Indirect sales through channel partner program			$	45,675					$	35,914
Direct sales			41,935						57,404
			$	87,610					$	93,318

The Company's product revenue from sales to enterprise customers and from sales to service provider customers for the three months ended March 31, 2024 and 2023 was as follows (in thousands):

			Three months ended
			March 31, 2024						March 31, 2023
Sales to enterprise customers			$	37,870					$	27,412
Sales to service provider customers			49,740						65,906
			$	87,610					$	93,318

The Company's product revenue and service revenue components by segment for the three months ended March 31, 2024 and 2023 were as follows (in thousands):

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			Three months ended
			March 31, 2024						March 31, 2023
Product revenue:
Cloud and Edge			$	31,513					$	42,839
IP Optical Networks			56,097						50,479
Total product revenue			$	87,610					$	93,318
Service revenue:
Maintenance:
Cloud and Edge			$	53,196					$	54,810
IP Optical Networks			15,185						15,778
Total maintenance revenue			68,381						70,588
Professional services:
Cloud and Edge			16,960						16,831
IP Optical Networks			6,713						5,422
Total professional services revenue			23,673						22,253
Total service revenue			$	92,054					$	92,841

Revenue Contract Balances

The timing of revenue recognition, billings and cash collections results in billed accounts receivable; unbilled receivables, which are contract assets; and customer advances and deposits, which are contract liabilities, in the Company's condensed consolidated balance sheets. Amounts are billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Completion of services and billing may occur subsequent to revenue recognition, resulting in contract assets. The Company may receive advances or deposits from its customers before revenue is recognized, resulting in contract liabilities that are classified as deferred revenue. These assets and liabilities are reported in the Company's condensed consolidated balance sheets on a contract-by-contract basis as of the end of each reporting period. Changes in the contract asset and liability balances during the three months ended March 31, 2024 were not materially impacted by any factors other than billing and revenue recognition. Nearly all of the Company's deferred revenue balance is related to services revenue, primarily customer support contracts. Unbilled receivables stem primarily from engagements where services have been performed; however, billing cannot occur until services are completed.

In some arrangements, the Company allows customers to pay for term-based software licenses and products over the term of the software license. The Company also sells SaaS-based software under subscription arrangements, with payment terms over the term of the SaaS agreement. Amounts recognized as revenue in excess of amounts billed are recorded as unbilled receivables. Unbilled receivables that are anticipated to be invoiced in the next twelve months are included in Accounts receivable on the Company's condensed consolidated balance sheets. The changes in the Company's accounts receivable, unbilled receivables and deferred revenue balances for the three months ended March 31, 2024 were as follows (in thousands):

			Accounts receivable						Unbilled accounts receivable						Deferred revenue (current)						Deferred revenue (long-term)
Balance at January 1, 2024			$	186,938					$	81,483					$	113,381					$	19,218
Increase (decrease), net			(43,634)						(12,289)						(2,785)						(5,199)
Balance at March 31, 2024			$	143,304					$	69,194					$	110,596					$	14,019

The Company recognized approximately $51 million of revenue in the three months ended March 31, 2024 that was recorded as deferred revenue at December 31, 2023 and approximately $48 million of revenue in the three months ended March 31, 2023 that was recorded as deferred revenue at December 31, 2022. Of the Company's deferred revenue reported as long-term in its condensed consolidated balance sheet at March 31, 2024, the Company expects that approximately $7 million will be recognized as revenue in 2025, approximately $4 million will be recognized as revenue in 2026 and approximately $3 million will be recognized as revenue in 2027 and beyond.

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All freight-related customer invoicing is recorded as revenue, while the shipping and handling costs that occur after control of the promised goods or services transfer to the customer are reported as fulfillment costs, a component of Cost of revenue - product in the Company's condensed consolidated statements of operations.

Deferred Commissions Cost

Sales commissions earned by the Company's employees are considered incremental and recoverable costs of obtaining a contract with a customer. These costs have been deferred on our condensed consolidated balance sheet and are being amortized over the expected life of the customer contract, which is generally five years. At both March 31, 2024 and December 31, 2023, the Company had $3.0 million of deferred sales commissions capitalized.

The Company has two reportable segments, which are intended to align with the manner in which the business is managed: Cloud and Edge, and IP Optical Networks.

The Cloud and Edge segment provides secure and reliable software and hardware products, solutions and services for enabling Voice over Internet Protocol ("VoIP") communications, Voice over Long-Term Evolution ("VoLTE") and Voice Over 5G ("VoNR") communications, and Unified Communications and Collaboration ("UC&C") within service provider and enterprise networks and from the cloud. The Cloud and Edge products are increasingly software-centric and cloud-native for deployment on private, public or hybrid cloud infrastructures, in data centers, on enterprise premises and within service provider networks. Ribbon's Cloud and Edge product portfolio consists primarily of its Session Border Controller ("SBC") products and its Network Transformation products.

The IP Optical Networks segment provides high-performance, secure solutions for IP networking and optical transport, supporting wireless networks including 5G, metro and edge aggregation, core networking, data center interconnect, legacy transformation and transport solutions for wholesale carriers. This portfolio is offered to service provider, enterprise and industry verticals with critical transport network infrastructures including utilities, government, defense, transportation, and education and research.

The Company has not provided segment asset information as such information is not provided to the CODM and accordingly, asset information is not used in assessing segment performance. Segment revenue and expenses included in the tables below represent direct revenue and expense attributable to each segment. Please see Note 4 for information regarding the allocation of goodwill between segments.

The CODM utilizes revenue and adjusted gross profit to measure and assess each segment's performance. The Company calculates adjusted gross profit by excluding from cost of revenue: amortization of acquired technology, stock-based compensation, and may also exclude other items in future periods that the Company believes are not part of the Company's core business. Adjusted gross profit is not a financial measure determined in accordance with U.S. GAAP, may not be comparable to similarly titled measures used by other companies, and should not be considered a substitute for gross profit or other results reported in accordance with U.S. GAAP. See below for a reconciliation of adjusted gross profit to gross profit which is the most directly comparable U.S. GAAP measure.

The tables below provide revenue, adjusted gross profit and depreciation expense by reportable segment for the three months ended March 31, 2024 and 2023 (in thousands):

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			Three months ended
			March 31, 2024						March 31, 2023
Segment revenue:
Cloud and Edge			$	101,669					$	114,480
IP Optical Networks			77,995						71,679
Revenue			$	179,664					$	186,159

			Three months ended
			March 31, 2024						March 31, 2023
Segment adjusted gross profit:
Cloud and Edge			$	67,119					$	69,975
IP Optical Networks			31,965						19,500
Total segment adjusted gross profit			99,084						89,475
Stock-based compensation expense			(578)						(684)
Amortization of acquired technology			(6,551)						(7,389)
Gross profit			$	91,955					$	81,402

			Three months ended
			March 31, 2024						March 31, 2023
Segment depreciation expense:
Cloud and Edge			$	2,333					$	2,499
IP Optical Networks			1,061						1,011
Depreciation expense			$	3,394					$	3,510

The following customer contributed 10% or more of the Company's revenue in the three months ended March 31, 2024 and 2023:

Three months ended

March 31, 2024

March 31, 2023

Verizon Communications Inc.

*

11%

* Less than 10% of total revenue.

At March 31, 2024 and December 31, 2023, no customer accounted for 10% or more of the Company's accounts receivable balance. The Company performs ongoing credit evaluations of its customers and generally does not require collateral on accounts receivable. The Company maintains an allowance for doubtful accounts and such losses have historically been within management's expectations.

The Company grants stock-based compensation to employees, officers and non-employee directors, as well as consultants and advisors of the Company and its subsidiaries under its Amended and Restated 2019 Incentive Award Plan which provides for the award of stock options, stock appreciation rights, restricted stock awards ("RSAs"), performance-based stock awards,

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restricted stock units ("RSUs"), performance-based stock units ("PSUs") and other stock- or cash-based awards.

Executive Equity Arrangements

Inducement Awards

In connection with his appointment as President and Chief Executive Officer of Ribbon on March 16, 2020, the Company awarded Bruce McClelland sign-on equity grants, comprised of RSUs and a PSU grant with both market and service conditions. As of March 31, 2024, the Company estimates that the market conditions surrounding the PSUs granted will not be met by the expiration date of September 1, 2024.

Performance-Based Stock Grants

In addition to granting RSAs and RSUs to its executives and certain of its employees, the Company also grants PSUs to certain of its executives and certain other employees. Vesting periods for RSAs, RSUs, and PSUs granted range from one to three years. PSUs granted consist of 60% that have both performance and service conditions (the "Performance PSUs") and 40% that have both market and service conditions (the "Market PSUs"). Each Performance PSU is comprised of three consecutive fiscal year performance periods beginning in the year of grant, with one-third of the Performance PSUs attributable to each fiscal year performance period. The Market PSUs have one three-year performance period, beginning January 1 in the year of grant and ending on December 31, three years thereafter. The number of shares of common stock underlying the PSUs that can be earned will not exceed 200% of the Performance or Market PSUs. Shares subject to PSUs that fail to be earned will be forfeited.

Restricted Stock Units

The activity related to the Company's RSUs for the three months ended March 31, 2024 was as follows:

			Shares						Weighted Average Grant Date Fair Value
Unvested balance at January 1, 2024			7,091,368						$	3.18
Granted			29,366						$	2.89
Vested			(888,189)						$	5.05
Forfeited			(200,229)						$	3.26
Unvested balance at March 31, 2024			6,032,316						$	2.90

The total grant date fair value of shares of restricted stock underlying RSUs that vested during the three months ended March 31, 2024 was $4.5 million.

Performance-Based Stock Units

The activity related to the Company's PSUs for the three months ended March 31, 2024 was as follows:

			Shares						Weighted Average Grant Date Fair Value
Unvested balance at January 1, 2024			6,297,931						$	2.07
Granted			—						$	—
Vested			(31,282)						$	6.40
Forfeited			(280,304)						$	9.40
Unvested balance at March 31, 2024			5,986,345						$	1.70

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The total grant date fair value of shares of restricted stock underlying PSUs that vested during the three months ended March 31, 2024 was $0.2 million.

Stock-Based Compensation

The condensed consolidated statements of operations include stock-based compensation for the three months ended March 31, 2024 and 2023 as follows (in thousands):

			Three months ended
			March 31, 2024						March 31, 2023
Product cost of revenue			$	106					$	149
Service cost of revenue			472						535
Research and development			1,068						1,262
Sales and marketing			1,157						2,129
General and administrative			1,719						1,773
			$	4,522					$	5,848

At March 31, 2024, there was $13.4 million, net of expected forfeitures, of unrecognized stock-based compensation expense related to unvested RSUs and PSUs. This expense is expected to be recognized over a weighted average period of approximately one year.

The Company has operating leases for corporate offices and research and development facilities and has historically had finance leases for certain equipment. Operating leases are reported separately in the Company's condensed consolidated balance sheets. Assets acquired under finance leases, if any, are included in Property and equipment, net, in the condensed consolidated balance sheets.

The Company determines if an arrangement is a lease at inception. A contract is determined to contain a lease component if the arrangement provides the Company with a right to control the use of an identified asset. Lease agreements may include lease and non-lease components. In such instances for all classes of underlying assets, the Company does not separate lease and non-lease components but rather, accounts for the entire arrangement under leasing guidance. Leases with an initial term of 12 months or less are not recorded on the balance sheet and lease expense for these leases is recognized on a straight-line basis over the lease term.

Right-of-use assets and lease liabilities are initially measured based on the present value of the future minimum fixed lease payments (i.e., fixed payments in the lease contract) over the lease term at the commencement date. As the Company's existing leases do not have a readily determinable implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of future minimum fixed lease payments. The Company calculates its incremental borrowing rate to reflect the interest rate that it would have to pay to borrow on a collateralized basis an amount equal to the lease payments in a similar economic environment over a similar term and considers its historical borrowing activities and market data from entities with comparable credit ratings in this determination. The measurement of the right-of-use asset also includes any lease payments made prior to the commencement date (excluding any lease incentives) and initial direct costs incurred. The Company assessed its right-of-use assets for impairment as of March 31, 2024 and December 31, 2023 and determined no impairment has occurred.

Lease terms may include options to extend or terminate the lease and the Company incorporates such options in the lease term when it has the unilateral right to make such an election and it is reasonably certain that the Company will exercise that option. In making this determination, the Company considers its prior renewal and termination history and planned usage of the assets under lease, incorporating expected market conditions.

For operating leases, lease expense for minimum fixed lease payments is recognized on a straight-line basis over the lease

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term. The expense for finance leases includes both interest and amortization expense components, with the interest component calculated based on the effective interest method and the amortization component calculated based on straight-line amortization of the right-of-use asset over the lease term. Lease contracts may contain variable lease costs, such as common area maintenance, utilities and tax reimbursements that vary over the term of the contract. Variable lease costs are not included in minimum fixed lease payments and as a result, are excluded from the measurement of the right-of-use assets and lease liabilities. The Company expenses all variable lease costs as incurred.

Certain leased facilities are being partially or fully vacated as part of the 2022 Restructuring Plan and for some of those facilities, the Company has no plans to enter into sublease agreements. Accordingly, the Company accelerated the amortization of those lease assets through the planned cease-use date of each facility, resulting in additional amortization expense $0.2 million in the three months ended March 31, 2023. No such accelerated amortization was recorded in the three months ended March 31, 2024. The Company did not record estimated future variable lease costs in the three months ended March 31, 2024 or 2023 related to the 2022 Restructuring Plan.

All incremental accelerated amortization and accruals for estimated future variable costs are included in Restructuring and related expense in the Company's condensed consolidated statements of operations. At March 31, 2024 and December 31, 2023, the Company had accruals of $1.4 million and $1.5 million, respectively, for all future anticipated variable lease costs related to these facilities. The Company may incur additional future expense if it is unable to sublease other locations included in the Facilities Initiative.

The Company leases its corporate offices and other facilities under operating leases, which expire at various times through 2033.

The Company's right-of-use lease assets and lease liabilities at March 31, 2024 and December 31, 2023 were as follows (in thousands):

			Classification						March 31, 2024						December 31, 2023
Assets:
Operating lease assets			Operating lease right-of-use assets						$	37,110					$	39,783
Liabilities:
Current Operating			Operating lease liabilities						$	14,213					$	15,739
Non-Current Operating			Operating lease liabilities, net of current						36,768						38,711
Total Operating lease liabilities									$	50,981					$	54,450

The components of lease expense for the three months ended March 31, 2024 and 2023 were as follows (in thousands):

									Three months ended
									March 31, 2024						March 31, 2023
Operating lease cost*									$	4,199					$	4,760
Short-term lease cost									3,441						3,427
Variable lease costs (costs excluded from minimum fixed lease payments)**									855						802
Sublease income									(260)						(430)
Net lease cost									$	8,235					$	8,559

* No accelerated amortization was recorded in the three months ended March 31, 2024. Operating lease costs for the three months ended March 31, 2023 included $0.2 million of accelerated amortization for certain assets partially or fully vacated with no intent or ability to sublease.

** No variable lease costs were accrued in the three months ended March 31, 2024 or 2023 for future estimated variable expenses related to certain assets partially or fully vacated with no intent or ability to sublease.

---

Cash flows related to the Company's leases in both the three months ended March 31, 2024 and 2023 were included in the measurement of operating lease liabilities and classified as operating cash flows and each totaled $4.8 million.

Other information related to the Company's leases as of March 31, 2024 and December 31, 2023 was as follows:

			March 31, 2024						December 31, 2023
Weighted average remaining lease term (years):
Operating leases			5.45						5.50
Weighted average discount rate:
Operating leases			7.04		%				6.34		%

Future minimum fixed lease payments under noncancelable leases at March 31, 2024 were as follows (in thousands):

			Operating
			leases
Remainder of 2024			$	13,873
2025			10,799
2026			9,018
2027			7,857
2028			6,452
2029			13,161
Total lease payments			61,160
Less: interest			(10,179)
Present value of lease liabilities			$	50,981

The Company recorded income tax provisions of $3.4 million and $1.5 million in the three months ended March 31, 2024 and 2023, respectively. These amounts reflect the Company's estimates of the effective rates expected to be applicable for the respective full years, adjusted for any discrete events, which are recorded in the period in which they occur. These estimates are reevaluated each quarter based on the Company's estimated tax expense for the full fiscal year. The estimated effective tax rate includes the impact of valuation allowances in various jurisdictions. The Company intends to continue to maintain a valuation allowance on its deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of the respective allowances.

The Company recognized revenue from its largest stockholder of $1.5 million and $0.8 million in the three months ended March 31, 2024 and 2023, respectively. Additionally, as discussed in Note 11, certain related party stockholders participated in the Private Placement.

Liabilities for Royalty Payments to the IIA

Prior to the Company's acquisition of ECI Telecom Group Ltd. ("ECI"), ECI had received research and development grants from the Office of the Innovation Authority of the Israeli Ministry of Economics (the "IIA"). The Company assumed ECI's contract with the IIA, which requires the Company to pay royalties to the IIA on proceeds from the sale of products which the

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Israeli government has supported by way of research and development grants. The royalties for grants prior to 2017 were calculated at the rates of 1.3% to 5.0% of the aggregated proceeds from the sale of such products developed at certain of the Company's R&D centers, up to an amount not exceeding 100% of such grants plus interest at LIBOR. Effective for grants approved in 2017 and subsequently, interest was calculated at the higher of LIBOR plus 1.5% to 2.75%. At March 31, 2024, the Company's maximum possible future royalties commitment, including $1.8 million of unpaid royalties accrued, was $20.6 million, including interest of $1.1 million, based on estimates of future product sales, grants received from the IIA not yet repaid, and management's estimation of products still to be sold.

Litigation

The Company is often a party to disputes and legal proceedings that it considers routine and incidental to its business, including those described below. The Company believes that it has meritorious defenses to the allegations made in the pending cases and intends to vigorously defend these lawsuits; however, the Company is unable currently to forecast the ultimate outcome of these or similar matters. Since it is difficult to predict the outcome of legal proceedings, it is possible that the ultimate outcomes could materially and adversely affect the Company’s business, financial position, results of operations or cash flows. Accordingly, with respect to these proceedings, the Company is currently unable to reasonably estimate the possible loss or range of possible loss.

Miller Complaint. On November 8, 2018, Ron Miller, a purported stockholder of the Company, filed a Class Action Complaint (the "Miller Complaint") in the United States District Court for the District of Massachusetts (the "Massachusetts District Court") against the Company and three of its former officers (collectively, the "Defendants"), claiming to represent a class of purchasers of Sonus common stock during the period from January 8, 2015 through March 24, 2015 and alleging violations of the federal securities laws. Similar to a previous complaint entitled Sousa et al. vs. Sonus Networks, Inc. et al., which was dismissed with prejudice by an order dated June 6, 2017, the Miller Complaint claims that the Defendants made misleading forward-looking statements concerning Sonus' expected fiscal first quarter of 2015 financial performance, which statements were also the subject of an August 7, 2018 Securities and Exchange Commission Cease and Desist Order, whose findings the Company neither admitted nor denied. The Miller plaintiffs are seeking monetary damages.

After the Miller Complaint was filed, several parties filed and briefed motions seeking to be selected by the Massachusetts District Court to serve as a Lead Plaintiff in the action. On June 21, 2019, the Massachusetts District Court appointed a group as Lead Plaintiffs and the Lead Plaintiffs filed an amended complaint on July 19, 2019. On August 30, 2019, the Defendants filed a motion to dismiss the Miller Complaint and, on October 4, 2019, the Lead Plaintiffs filed an opposition to the motion to dismiss. There was an oral argument on the motion to dismiss on February 12, 2020, and on October 20, 2022 the court denied the motion to dismiss. In June 2023, the Defendants agreed to a settlement in principle with the named plaintiffs, and final approval of the settlement was provided by the court on April 24, 2024. The settlement provided a release of all claims asserted in the litigation to all Defendants, who continue to deny liability. The $4.5 million settlement amount was funded by the provider of the Company's Directors and Officers liability insurance policy.

Charter Complaint. On September 19, 2022, Charter Communications Operating, LLC (“Charter”) filed two complaints against two of our subsidiaries (Sonus Networks, Inc. and Ribbon Communications Operating Company, Inc.) alleging breach of contract with respect to indemnification obligations purportedly owed to Charter in connection with Charter’s legal dispute with Sprint Communications Company L.P., which was settled by Charter in March 2022. One complaint was filed in the Supreme Court of the State of New York, in New York County; the second complaint was filed by Charter as well as co-plaintiffs Charter Communications Holding Company, LLC and Bright House Networks, LLC, in the Superior Court of the State of Delaware in and for New Castle County. In both complaints, Charter is seeking monetary damages. The Company filed its answer to the first complaint file in New York on December 7, 2022 and to the second complaint filed in Delaware on January 9, 2023. Discovery is on-going and the court in the Delaware complaint has set a preliminary trial date of January 2025.

WideOpenWest Complaint. On August 9, 2023, WideOpenWest, Inc. and WideOpenWest Finance, LLC (collectively, “WOW”) filed a complaint against Ribbon alleging breach of contract with respect to indemnification obligations purportedly owed to WOW in connection with WOW’s legal dispute with Sprint Communications Company L.P., which was settled by WOW in the second quarter of 2023. The complaint was filed in the 429th Judicial District of the District Court of the State of Texas, in Collin County, Texas and has since been transferred to the 493rd Judicial District Court in Collin County. In the

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complaint, WOW is seeking monetary damages. The Company filed its answer to the complaint on October 5, 2023. Discovery is on-going and the court has set a preliminary trial date of December 2024.

On May 15, 2024, the Company entered into a binding commitment letter (the "Commitment Letter") with HPS Investment Partners, LLC ("HPS") and WhiteHorse Capital Management, LLC ("WhiteHorse" and, together with HPS, the "Lenders"), pursuant to which the Lenders have committed to provide the Company with a $385 million senior secured credit facility (the "Refinancing Facility") comprised of (i) a $350 million term loan and (ii) a $35 million revolving credit facility. The funds from the Refinancing Facility will be used to (a) repay 100% of the amounts outstanding under the 2020 Credit Facility (b) redeem in full the Company's outstanding Series A preferred stock and (c) pay fees and expenses related to the Refinancing Facility. Any excess proceeds will be used by the Company for working capital.

The funding of the Refinancing Facility is subject to satisfaction of customary closing conditions. The Company expects the Refinancing Facility to close and fund no later than June 30, 2024.

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v3.24.1.1.u2

Cover - shares	3 Months Ended
	Mar. 31, 2024	May 10, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-38267
Entity Registrant Name	RIBBON COMMUNICATIONS INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-1669692
Entity Address, Address Line One	6500 Chase Oaks Boulevard, Suite 100,
Entity Address, City or Town	Plano
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75023
City Area Code	978
Local Phone Number	614-8100
Title of 12(b) Security	Common Stock, par value $0.0001
Trading Symbol	RBBN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		173,909,887
Entity Central Index Key	0001708055
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false

v3.24.1.1.u2

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 30,931	$ 26,630
Accounts receivable, net	212,498	268,421
Inventory	80,758	77,521
Other current assets	44,943	46,146
Total current assets	369,130	418,718
Property and equipment, net	40,758	41,820
Intangible assets, net	224,880	238,087
Goodwill	300,892	300,892
Deferred income taxes	72,438	69,761
Operating lease right-of-use assets	37,110	39,783
Other assets	33,252	35,092
Total assets	1,078,460	1,144,153
Current liabilities:
Current portion of term debt	228,168	35,102
Accounts payable	66,847	85,164
Accrued expenses and other	84,491	91,687
Operating lease liabilities	14,213	15,739
Deferred revenue	110,596	113,381
Total current liabilities	504,315	341,073
Long-term debt, net of current	0	197,482
Warrant liability	5,927	5,295
Preferred stock liability, $0.01 par value per share; 10,000,000 shares authorized, 55,000 shares issued and outstanding ($56,650 liquidation preference)	56,204	53,337
Operating lease liabilities, net of current	36,768	38,711
Deferred revenue, net of current	14,019	19,218
Deferred income taxes	5,616	5,616
Other long-term liabilities	30,953	30,658
Total liabilities	653,802	691,390
Commitments and contingencies (Note 19)
Stockholders' equity:
Common stock, $0.0001 par value per share; 240,000,000 shares authorized; 172,714,429 shares issued and outstanding at March 31, 2024; 172,083,667 shares issued and outstanding at December 31, 2023	17	17
Additional paid-in capital	1,962,602	1,958,909
Accumulated deficit	(1,550,311)	(1,519,950)
Accumulated other comprehensive income	12,350	13,787
Total stockholders' equity	424,658	452,763
Total liabilities and stockholders' equity	$ 1,078,460	$ 1,144,153

v3.24.1.1.u2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	55,000	55,000
Preferred stock, shares outstanding (in shares)	55,000	55,000
Preferred stock, liquidation preference, value	$ 56,650	$ 56,650
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	240,000,000	240,000,000
Common stock, shares issued (in shares)	172,714,429	172,083,667
Common stock, shares outstanding (in shares)	172,714,429	172,083,667

v3.24.1.1.u2

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Total revenue	$ 179,664	$ 186,159
Cost of revenue:
Total cost of revenue	87,709	104,757
Gross profit	91,955	81,402
Operating expenses:
Research and development	45,763	51,304
Sales and marketing	34,716	35,399
General and administrative	15,191	14,045
Amortization of acquired intangible assets	6,706	7,264
Acquisition-, disposal- and integration-related	0	1,642
Restructuring and related	3,065	6,937
Total operating expenses	105,441	116,591
Loss from operations	(13,486)	(35,189)
Interest expense, net	(5,987)	(6,422)
Other (expense) income, net	(7,513)	4,772
Loss before income taxes	(26,986)	(36,839)
Income tax provision	(3,375)	(1,466)
Net loss	$ (30,361)	$ (38,305)
Loss per share:
Basic (in dollars per share)	$ (0.18)	$ (0.23)
Diluted (in dollars per share)	$ (0.18)	$ (0.23)
Weighted average shares used to compute loss per share:
Basic (in shares)	172,428	168,541
Diluted (in shares)	172,428	168,541
Product
Revenue:
Total revenue	$ 87,610	$ 93,318
Cost of revenue:
Total cost of revenue	45,794	62,063
Service
Revenue:
Total revenue	92,054	92,841
Cost of revenue:
Total cost of revenue	35,364	35,305
Amortization of acquired technology
Cost of revenue:
Total cost of revenue	$ 6,551	$ 7,389

v3.24.1.1.u2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (30,361)	$ (38,305)
Other comprehensive income (loss), net of tax:
Unrealized loss on interest rate swap, net of reclassifications and amortization into earnings	(1,321)	(5,900)
Reclassification of gain to other income (expense), net upon sale of interest rate swap	0	(5,099)
Foreign currency translation adjustments	(116)	(151)
Other comprehensive loss, net of tax	(1,437)	(11,150)
Comprehensive loss, net of tax	$ (31,798)	$ (49,455)

v3.24.1.1.u2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive (loss) income
Beginning balance (in shares) at Dec. 31, 2022		168,324,995
Beginning balance at Dec. 31, 2022	$ 518,427	$ 17	$ 1,941,569	$ (1,453,744)	$ 30,585
Increase (Decrease) in Stockholders' Equity
Exercise of stock options (in shares)		573
Exercise of stock options	1		1
Vesting of restricted stock awards and units (in shares)		1,020,277
Vesting of performance-based stock units (in shares)		381,071
Shares of restricted stock returned to the Company under net share settlements to satisfy tax withholding obligations (in shares)		(496,937)
Shares of restricted stock returned to the Company under net share settlements to satisfy tax withholding obligations	(1,893)		(1,893)
Stock-based compensation expense	5,848		5,848
Other comprehensive loss	(11,150)				(11,150)
Net loss	(38,305)			(38,305)
Ending balance (in shares) at Mar. 31, 2023		169,229,979
Ending balance at Mar. 31, 2023	$ 472,928	$ 17	1,945,525	(1,492,049)	19,435
Beginning balance (in shares) at Dec. 31, 2023	172,083,667	172,083,667
Beginning balance at Dec. 31, 2023	$ 452,763	$ 17	1,958,909	(1,519,950)	13,787
Increase (Decrease) in Stockholders' Equity
Exercise of stock options (in shares)		8,624
Exercise of stock options	17		17
Vesting of restricted stock awards and units (in shares)		888,189
Vesting of performance-based stock units (in shares)		31,282
Shares of restricted stock returned to the Company under net share settlements to satisfy tax withholding obligations (in shares)		(297,333)
Shares of restricted stock returned to the Company under net share settlements to satisfy tax withholding obligations	(846)		(846)
Stock-based compensation expense	4,522		4,522
Other comprehensive loss	(1,437)				(1,437)
Net loss	$ (30,361)			(30,361)
Ending balance (in shares) at Mar. 31, 2024	172,714,429	172,714,429
Ending balance at Mar. 31, 2024	$ 424,658	$ 17	$ 1,962,602	$ (1,550,311)	$ 12,350

v3.24.1.1.u2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (30,361)	$ (38,305)
Adjustments to reconcile net loss to cash flows provided by operating activities:
Depreciation and amortization of property and equipment	3,394	3,510
Amortization of intangible assets	13,257	14,653
Amortization of debt issuance costs	716	1,065
Amortization of accumulated other comprehensive gain related to interest rate swap	(1,756)	0
Stock-based compensation	4,522	5,848
Deferred income taxes	(2,620)	(6,048)
Gain on sale of swap	0	(7,301)
Change in fair value of warrant liability	632	0
Change in fair value of preferred stock liability	1,512	0
Dividends accrued on preferred stock liability	1,355	0
Foreign currency exchange (gains) losses	1,144	(2,185)
Changes in operating assets and liabilities:
Accounts receivable	55,384	19,742
Inventory	(4,379)	(2,917)
Other operating assets	7,923	15,031
Accounts payable	(17,837)	(10,405)
Accrued expenses and other long-term liabilities	(11,800)	11,521
Deferred revenue	(7,986)	6,924
Net cash provided by operating activities	13,100	11,133
Cash flows from investing activities:
Purchases of property and equipment	(2,513)	(2,413)
Purchases of software licenses	(150)	0
Net cash used in investing activities	(2,663)	(2,413)
Cash flows from financing activities:
Borrowings under revolving line of credit	15,000	0
Principal payments on revolving line of credit	(15,000)	0
Principal payments of term debt	(5,014)	(80,015)
Payment of debt issuance costs	0	(1,562)
Proceeds from issuance of preferred stock and warrant liabilities	0	53,350
Proceeds from the exercise of stock options	17	1
Payment of tax obligations related to vested stock awards and units	(846)	(1,893)
Net cash used in financing activities	(5,843)	(30,119)
Effect of exchange rate changes on cash and cash equivalents	(293)	171
Net increase (decrease) in cash and cash equivalents	4,301	(21,228)
Cash and cash equivalents, beginning of year	26,630	67,262
Cash and cash equivalents, end of period	30,931	46,034
Supplemental disclosure of cash flow information:
Interest paid	6,322	4,757
Income taxes paid	3,138	1,517
Income tax refunds received	474	289
Supplemental disclosure of non-cash investing activities:
Capital expenditures incurred, but not yet paid	1,889	1,579
Inventory transfers to property and equipment	507	656
Supplemental disclosure of non-cash financing activities:
Fair value of vested restricted and performance-based stock grants	$ 2,610	$ 5,332

v3.24.1.1.u2

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION Business Ribbon Communications Inc. ("Ribbon" or the "Company") is a leading global provider of communications technology to service providers and enterprises. The Company provides a broad range of software and high-performance hardware products, network solutions, and services that enable the secure delivery of data and voice communications, and high-bandwidth networking and connectivity for residential consumers and for small, medium, and large enterprises and industry verticals such as finance, education, government, utilities, and transportation. Ribbon's mission is to create a recognized global technology leader providing cloud-centric solutions that enable the secure exchange of information, with unparalleled scale, performance, and elasticity. The Company is headquartered in Plano, Texas, and has a global presence with research and development, or sales and support locations in over thirty countries around the world. Basis of Presentation In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments, consisting only of normal recurring items, necessary for their fair presentation with accounting principles generally accepted in the United States of America ("GAAP") and with the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). Interim results are not necessarily indicative of results for a full year or any future interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2023, as amended (the "Annual Report"), which was filed with the SEC on February 28, 2024. Operating Segments The Company's chief operating decision maker (the "CODM") is its president and chief executive officer. The CODM assesses the Company's performance based on the performance of two separate organizations within Ribbon: the Cloud and Edge segment ("Cloud and Edge") and the IP Optical Networks segment ("IP Optical Networks"). Significant Accounting Policies The Company's significant accounting policies are disclosed in Note 2 to the Consolidated Financial Statements included in the Annual Report. There were no material changes to the significant accounting policies during the three months ended March 31, 2024. Principles of Consolidation The condensed consolidated financial statements include the accounts of Ribbon and its wholly-owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. Use of Estimates and Judgments The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and judgments relied upon in preparing these condensed consolidated financial statements include revenue recognition for multiple element arrangements, inventory valuations, assumptions used to determine the fair value of stock-based compensation and the Preferred Stock and Warrants, intangible asset and goodwill valuations, including impairments, warranty accruals, legal contingencies and recoverability of Ribbon's net deferred tax assets and the related valuation allowances. Ribbon regularly assesses these estimates and records changes in estimates in the period in which they become known. Ribbon bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates. Transfers of Financial Assets The Company's IP Optical Networks segment maintains customer receivables factoring agreements with a number of financial institutions. Under the terms of these agreements, the Company may transfer receivables to the financial institutions, on a non-recourse basis, provided that the financial institutions approve the receivables in advance. The Company maintains credit insurance policies from major insurance providers or obtains letters of credit from the customers for a majority of its factored trade receivables. The Company accounts for the factoring of its financial assets as a sale of the assets and records the factoring fees, when incurred, as a component of interest expense in the condensed consolidated statements of operations, and the proceeds from the sales of receivables are included in cash from operating activities in the condensed consolidated statements of cash flows. Factoring of accounts receivable and associated fees for the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Accounts receivable sold 20,992  21,061  Less factoring fees (391) (455) Net cash proceeds 20,601  20,606  Going Concern Assessment and Management Plans The accompanying condensed consolidated financial statements are prepared in accordance with GAAP applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company's 2020 Credit Facility (as defined in Note 9) requires quarterly payments of $10.0 million each in the second, third and fourth quarters of 2024, with the remaining balance of $200.4 million due on March 3, 2025. The Company does not have sufficient cash on hand or available liquidity to repay the $200.4 million due on March 3, 2025. In response to these conditions, management's plans include refinancing the 2020 Credit Facility. The Company has entered into a binding commitment letter to refinance the 2020 Credit Facility. See Note 20 - Subsequent Event. The refinance contemplated by the binding commitment letter is expected to close no later than June 30, 2024. However, because the credit facility contemplated by the commitment letter has not yet been finalized, it cannot be deemed to be within the Company's control. As a result, such plans cannot be deemed probable and do not alleviate the substantial doubt raised about the Company's ability to continue as a going concern. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Recent Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (the "FASB") issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”), which increases the disclosure requirements around rate reconciliation information and certain types of income taxes companies are required to pay. ASU 2023-09 will be effective for the Company beginning in 2025, with early adoption permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which improves reportable segment disclosure requirements, including enhancement of the disclosures of significant segment expenses and interim disclosure requirements, to enable investors to better understand an entity's overall performance and assess potential future cash flows. ASU 2023-07 will be effective for the Company annually beginning in 2024 and on an interim basis beginning in 2025, with early adoption permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures. In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC's disclosure Update and Simplification Initiative (“ASU 2023-06”), which amends the disclosure or presentation requirements related to various subtopics in the FASB Accounting Standards Codification. This ASU was issued in response to, and to align GAAP with, the SEC's August 2018 final rule that updates and simplifies disclosure requirements. The effective date for the Company for each amendment will be the date on which the SEC's removal of that related disclosure requirement becomes effective, with early adoption prohibited. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures. On February 1, 2023, the FASB staff noted that they believe that the Pillar 2 tax, established by the OECD and intended to apply for tax years beginning in 2024, would be an alternative minimum tax and therefore deferred tax assets would not need to be recognized related to this parallel taxing system. On February 2, 2023, the OECD issued administrative guidance providing transition and safe harbor rules around the implementation of the Pillar 2 global minimum tax. Under an additional transitional safe harbor released July 17, 2023, the undertaxed profits rule top-up tax will not be applied by any constituent entity's jurisdiction of residence with respect to income earned by a company's ultimate parent entity in its jurisdiction of residence, if the ultimate parent entity's jurisdiction has a corporate tax rate of at least 20%. This transition safe harbor will apply to fiscal years beginning on or before December 31, 2025 and ending before December 31, 2026. The Company is closely monitoring developments and evaluating the impacts these new rules will have on its tax rate, including eligibility to qualify for these safe harbor rules. Based upon preliminary calculations for calendar year 2024, the Company anticipates that it will meet the safe harbors in most jurisdictions, and any remaining top-up tax should be immaterial.

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EARNINGS (LOSS) PER SHARE	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
EARNINGS (LOSS) PER SHARE	EARNINGS (LOSS) PER SHARE Basic earnings (loss) per share is computed by dividing net income (loss) by the weighted average number of shares outstanding during the period. For periods in which the Company reports net income, diluted net earnings per share is determined by using the weighted average number of common and dilutive common equivalent shares outstanding during the period, unless the effect is antidilutive. The shares used to compute loss per share were as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Weighted average shares outstanding - basic 172,428  168,541  Potential dilutive common shares —  —  Weighted average shares outstanding - diluted 172,428  168,541  Options to purchase the Company's common stock and unvested restricted and performance-based stock units aggregating 12.1 million and 11.9 million shares were excluded from the computation of diluted loss per share for the three months ended March 31, 2024 and 2023, respectively, because their effect would have been antidilutive. On March 28, 2023, the Company issued 55,000 shares of newly designated Series A Preferred Stock (the "Preferred Stock") to investors in a private placement offering at a price of $970 per share, along with 4.9 million warrants (the "Warrants") to purchase shares of the Company's common stock, par value $0.0001 per share (the "Private Placement"), at the exercise price of $3.77 per share. The proceeds from the Private Placement were approximately $53.4 million, including approximately $10 million from existing related party stockholders (See Note 11). As of March 31, 2024, the potential number of dilutive shares from the Warrants totaled 4.9 million shares. However, there was no impact on weighted average shares outstanding from these Warrants for the three months ended March 31, 2024 as the average share price of the Company's common stock was below the exercise price of $3.77 per share and their effect would have been antidilutive. For the three months ended March 31, 2023, the potential effect from the Warrants on weighted average shares outstanding for the calculation of diluted earnings (loss) per share was de minimis. Dividends payable on the Preferred Stock are not an adjustment to net income (loss) used for the calculation of diluted earnings (loss) per share as these dividends are included in the fair value adjustment of the Preferred Stock which is reflected in Other (expense) income, net.

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INVENTORY	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):   March 31, 2024 December 31, 2023 On-hand final assemblies and finished goods inventories $ 98,290  $ 93,077  Deferred cost of goods sold 1,927  3,269  100,217  96,346  Less noncurrent portion (included in Other assets) (19,459) (18,825) Current portion $ 80,758  $ 77,521

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INTANGIBLE ASSETS AND GOODWILL	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND GOODWILL	INTANGIBLE ASSETS AND GOODWILL The Company's intangible assets at March 31, 2024 and December 31, 2023 consisted of the following (in thousands): March 31, 2024 Weighted average amortization period (years) Cost Accumulated amortization Net carrying value Developed technology 7.84 $ 340,380  $ 245,163  $ 95,217  Customer relationships 11.86 268,140  141,423  126,717  Trade names 3.88 5,000  4,927  73  Software licenses 3.00 5,486  2,613  2,873  9.50 $ 619,006  $ 394,126  $ 224,880  December 31, 2023 Weighted average amortization period (years) Cost Accumulated amortization Net carrying value Developed technology 7.84 $ 340,380  $ 239,066  $ 101,314  Customer relationships 11.86 268,140  134,743  133,397  Trade names 3.88 5,000  4,901  99  Software licenses 3.00 5,436  2,159  3,277  9.51 $ 618,956  $ 380,869  $ 238,087  Estimated future amortization expense for the Company's intangible assets at March 31, 2024 was as follows (in thousands): Years ending December 31, Remainder of 2024 $ 37,557  2025 44,105  2026 39,056  2027 33,939  2028 23,400  2029 18,379  Thereafter 28,444  $ 224,880  There were no changes to the carrying value of the Company's goodwill in the three months ended March 31, 2024 and 2023. The components of goodwill at both March 31, 2024 and 2023 were as follows (in thousands): Cloud and Edge IP Optical Networks Total   Goodwill $ 392,302  $ 191,996  $ 584,298    Accumulated impairment losses (167,406) (116,000) (283,406) $ 224,896  $ 75,996  $ 300,892

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FAIR VALUE HIERARCHY	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
FAIR VALUE HIERARCHY	FAIR VALUE HIERARCHY The carrying amounts of the Company's cash equivalents, accounts receivable, accounts payable and borrowings under a revolving credit facility in the condensed consolidated balance sheets approximates fair value due to the immediate or short-term nature of these financial instruments. Ribbon's term debt balance as of March 31, 2024 and December 31, 2023 of $230.4 million and $235.4 million, respectively, had a fair value of approximately $231.5 million and $235.1 million, respectively. Our Preferred Stock and Warrants liabilities had a combined fair value of $62.1 million as of March 31, 2024, including cumulative dividends on the Preferred Stock of $5.3 million. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The three-tier fair value hierarchy is based on the level of independent, objective evidence surrounding the inputs used to measure fair value. A financial instrument's categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The fair value hierarchy is as follows: Level 1. Level 1 applies to assets or liabilities for which there are quoted prices in active markets for identical assets or liabilities. The Company had no assets or liabilities fair valued using Level 1 input at March 31, 2024 or December 31, 2023. Level 2. Level 2 applies to assets or liabilities for which there are inputs that are directly or indirectly observable in the marketplace, such as quoted prices for similar assets or liabilities in active markets or quoted prices for identical assets or liabilities in markets with insufficient volume or infrequent transactions (less active markets). At December 31, 2023, the Company determined the fair value of its defined benefit plans' assets using Level 2 input. There were no significant changes to the Company's defined benefit plans' assets during the three months ended March 31, 2024 that required the calculation of their fair value as of March 31, 2024. Level 3. Level 3 applies to assets or liabilities for which there are unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of the assets or liabilities. At March 31, 2024 and December 31, 2023, the fair value of the Company's Preferred Stock and Warrants were determined using Level 3 input.

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ACCRUED EXPENSES AND OTHER	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
ACCRUED EXPENSES AND OTHER	ACCRUED EXPENSES AND OTHER Accrued expenses at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):   March 31, 2024 December 31, 2023 Employee compensation and related costs $ 29,505  $ 33,682  Professional fees 19,148  19,702  Taxes payable 3,653  8,383  Other 32,185  29,920  $ 84,491  $ 91,687

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WARRANTY ACCRUALS	3 Months Ended
	Mar. 31, 2024
Guarantees and Product Warranties [Abstract]
WARRANTY ACCRUALS	WARRANTY ACCRUALS The changes in the Company's accrual balance in the three months ended March 31, 2024 were as follows (in thousands): Balance at January 1, 2024 $ 12,243  Current period provisions 1,347  Settlements (1,334) Balance at March 31, 2024 $ 12,256

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RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES	3 Months Ended
	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES	RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES The Company recorded restructuring and related expense aggregating $3.1 million and $6.9 million in the three months ended March 31, 2024 and 2023, respectively. Restructuring and related expense includes restructuring expense (primarily severance and related costs), estimated future variable lease costs for vacated properties with no intent or ability of sublease, and accelerated rent amortization expense. For restructuring events that involve lease assets and liabilities, the Company applies lease reassessment and modification guidance and evaluates the right-of-use assets for potential impairment. If the Company plans to exit all or distinct portions of a facility and does not have the ability or intent to sublease, the Company will accelerate the amortization of each of those lease components through the vacate date. The accelerated amortization is recorded as a component of Restructuring and related expense in the Company's condensed consolidated statements of operations. Related variable lease expenses will continue to be expensed as incurred through the vacate date, at which time the Company will reassess the liability balance to ensure it appropriately reflects the remaining liability associated with the premises and record a liability for the estimated future variable lease costs. Accelerated amortization of lease assets is recognized from the date that the Company commences the plan to fully or partially vacate a facility, for which there is no intent or ability to enter into a sublease, through the final vacate date. Accelerated amortization of lease assets that are included as a component of restructuring and related expense are excluded from the restructuring accrual activity tables below, as the liability for lease payments for these facilities is included as a component of current and noncurrent Operating lease liabilities in the Company's condensed consolidated balance sheets at March 31, 2024 and December 31, 2023 (see Note 16). The Company may incur additional future expense if it is unable to sublease other locations included in the Company's facilities consolidation initiatives. Restructuring and related expense for the three months ended March 31, 2024 and 2023 was comprised of the following (in thousands): Three months ended March 31, 2024 March 31, 2023 Severance and related costs $ 1,616  $ 5,708  Variable and other facilities-related costs 1,449  $ 1,006  Accelerated amortization of lease assets due to cease-use —  $ 223  $ 3,065  $ 6,937  2023 Restructuring Plan On February 22, 2023, the Company's Board of Directors approved a strategic restructuring program (the "2023 Restructuring Plan") to streamline the Company's operations in order to support the Company's investment in critical growth areas. The 2023 Restructuring Plan includes, among other things, charges related to a workforce reduction. Any potential positions eliminated in countries outside the United States are subject to local law and consultation requirements. In connection with the 2023 Restructuring Plan, the Company recorded restructuring and related expense of $1.6 million and $5.7 million in the three months ended March 31, 2024 and 2023, respectively, consisting entirely of severance related costs. A summary of the 2023 Restructuring Plan accrual activity for the three months ended March 31, 2024 is as follows (in thousands): Balance at January 1, 2024 Initiatives charged to expense Cash payments Net transfer to operating lease accounts Balance at March 31, 2024 Severance $ 671  $ 1,616  $ (1,284) $ —  $ 1,003  2022 Restructuring Plan On February 14, 2022, the Company's Board of Directors approved a strategic restructuring program (the "2022 Restructuring Plan") to streamline the Company's operations in order to support the Company's investment in critical growth areas. The 2022 Restructuring Plan includes, among other things, charges related to a consolidation of facilities and a workforce reduction. Any positions eliminated in countries outside the United States are subject to local law and consultation requirements. The Company recorded restructuring and related expense of $1.4 million and $1.2 million in the three months ended March 31, 2024 and 2023, respectively, in connection with the 2022 Restructuring Plan. The amount for the three months ended March 31, 2024 was comprised of $1.4 million for facilities-related costs. The amount for the three months ended March 31, 2023 was comprised of $1.0 million for variable and other facilities-related costs and $0.2 million for accelerated amortization of lease assets no longer being used with no ability or intent to sublease. A summary of the 2022 Restructuring Plan accrual activity for the three months ended March 31, 2024 is as follows (in thousands): Balance at January 1, 2024 Initiatives charged to expense Cash payments Balance at March 31, 2024 Variable and other facilities-related costs $ 468  1,449  (1,495) $ 422  Balance Sheet Classification The current portions of accrued restructuring were $1.4 million and $1.1 million at March 31, 2024 and December 31, 2023, respectively, and are included as components of Accrued expenses in the condensed consolidated balance sheets. The long-term portions of accrued restructuring are included as components of Other long-term liabilities in the condensed consolidated balance sheets. The long-term portions of accrued restructuring were $1.0 million and $1.1 million at March 31, 2024 and December 31, 2023, respectively.

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DEBT	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
DEBT	DEBT 2020 Credit Facility On March 3, 2020, the Company entered into a Senior Secured Credit Facilities Credit Agreement (as amended, the "2020 Credit Facility"), by and among the Company, as a guarantor, Ribbon Communications Operating Company, Inc., as the borrower ("Borrower"), Citizens Bank, N.A. ("Citizens"), Santander Bank, N.A., and others as lenders ("Lenders"). The proceeds from the Credit Agreement were used, in part, to pay off in full all obligations of the Company under the 2019 Credit Facility. The 2020 Credit Facility originally provided for $500 million of commitments from the Lenders to the Borrower, comprised of $400 million in term loans (the "2020 Term Loan Facility") and a $100 million facility available for revolving loans (the "2020 Revolving Credit Facility"). Under the 2020 Revolving Credit Facility, a $30 million sublimit was originally available for letters of credit and a $20 million sublimit remains available for swingline loans. The indebtedness and other obligations under the 2020 Credit Facility are unconditionally guaranteed on a senior secured basis by the Company, Edgewater Networks, Inc., a wholly-owned subsidiary of the Company, and GENBAND Inc., a wholly-owned subsidiary of the Company (together, the "Guarantors"). The 2020 Credit Facility is secured by first-priority liens on substantially all of the assets of the Borrower and the Guarantors, including substantially all of the assets of the Company. The 2020 Credit Facility requires compliance with certain financial covenants, including a minimum Consolidated Fixed Charge Coverage Ratio and a maximum Consolidated Net Leverage Ratio (each as defined in the 2020 Credit Facility, and each tested on a quarterly basis). On August 18, 2020, the Company entered into the First Amendment to the 2020 Credit Facility in which $75 million of the 2020 Term Loan Facility was assigned from Citizens to a new lender and designated as the Term B Loan. The remaining $325 million of the 2020 Term Loan Facility was deemed the Term A Loan. The Term A Loan and the 2020 Revolving Credit Facility mature in March 2025 and originally bore interest at the Borrower's option at either the LIBOR rate plus a margin ranging from 1.50% to 3.50% per year, or the base rate plus 0.50%, or the prime rate plus a margin ranging from 0.50% to 2.50% per year (the "Applicable Margin"). The Applicable Margin varied depending on the Company's Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility). The Term B Loan was scheduled to mature in March 2026 and bore interest, at the Borrower's option, at either the LIBOR rate plus a margin of 7.50% per year, or the base rate (the highest of the Federal Funds Effective Rate (as defined in the First Amendment) plus 0.50%, or the prime rate. On December 1, 2020, the Company entered into the Second Amendment to the 2020 Credit Facility to obtain consent for an equity exchange with AVCT in connection with the sale of our Kandy Communications business, as well as to amend certain other provisions of the 2020 Credit Facility. On March 3, 2021, the Company entered into the Third Amendment to the 2020 Credit Facility which provided for an incremental term loan facility in the principal amount of $74.6 million, the proceeds of which were used to consummate an open market purchase of all outstanding amounts under the Term B Loan, resulting in the assignment and immediate cancellation of the Term B Loan, such that the outstanding amount under the Term A Loan and incremental term loan facility were combined and held by the Lenders (the "2020 Term Loan") with the same terms as the Term A Loan. The Company wrote off $2.5 million of capitalized debt issuance costs in connection with the Third Amendment. On March 10, 2022, the Company entered into the Fourth Amendment to the 2020 Credit Facility to increase the Maximum Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility) and in conjunction the Company made a $15.0 million prepayment that was applied to the final payment due on the maturity date. On June 30, 2022, the Company entered into the Fifth Amendment to the 2020 Credit Facility (the "Fifth Amendment") to increase the Maximum Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility) for 2022, with the fourth quarter of 2022 increased to 4.75:1.00, the first and second quarters of 2023 declining to 3.25:1.00, and in all subsequent quarters the ratio was to be fixed at 3.00:1.00. Also, the Fifth Amendment reduced the minimum Consolidated Fixed Charge Coverage Ratio (as defined in the 2020 Credit Facility) in 2022, with the fourth quarter of 2022 reduced to 1.10:1.00 and in all subsequent quarters the ratio was to be fixed at 1.25:1.00. In addition, the Fifth Amendment increased the maximum rate at which loans were to bear interest if the Company's Consolidated Net Leverage Ratio for any quarter was greater than 4.50:1.00. Specifically, loans incurred would bear interest, at the Borrower’s option, at either LIBOR plus a margin ranging from 1.50% to 4.50% per year, or the base rate plus 0.50%, or the prime rate plus a margin ranging from 0.50% to 3.50% per year. The Fifth Amendment also allows the Company to incur junior secured or unsecured debt in an amount no less than $50 million, subject to certain conditions, including the requirement that 50% of the aggregate amount of such incurred debt (net of certain costs, fees and other amounts) must be applied to prepay the 2020 Credit Facility, and compliance with certain leverage ratio-based covenant exceptions. In connection with the Fifth Amendment, the Company made a $10.0 million voluntary prepayment that was applied to the final payment due on the maturity date. Subsequent to the Fifth Amendment, the Company is required to make quarterly principal payments on the 2020 Term Loan aggregating approximately $5.0 million per quarter through March 31, 2024 and $10.0 million in each of the three quarters thereafter, with the remaining and final payment due on the maturity date in March 2025. On March 24, 2023, the Company entered into the Sixth Amendment to the 2020 Credit Facility (the “Sixth Amendment”) effective March 30, 2023. The Sixth Amendment, among other things, increased the Maximum Consolidated Net Leverage Ratio (as defined in the 2020 Credit Facility), with the first, second and third quarters of 2023 increasing to 4.50:1.00. In the fourth quarter of 2023 and the first quarter of 2024, the Maximum Consolidated Net Leverage Ratio declines to 4.25:1.00 and 4.00:1.00, respectively. In all subsequent quarters, the Maximum Consolidated Senior Net Leverage Ratio will be fixed at 3.00:1.00 and the Maximum Consolidated Net Leverage Ratio will be fixed at 4.00:1.00. Also, the Sixth Amendment reduced the minimum Consolidated Fixed Charge Coverage Ratio (as defined in the 2020 Credit Facility) to 1.10:1.00 through the first quarter of 2024 and in all subsequent quarters the ratio will be fixed at 1.25:1.00. The Sixth Amendment reduced the maximum borrowings allowed under the 2020 Revolving Credit Facility from $100 million to $75 million and the sublimit available for letters of credit was reduced from $30 million to $20 million. In addition, the Sixth Amendment replaced LIBOR with the Secured Overnight Financing Rate ("SOFR") as the alternative rate that may be used by the Company for calculating interest owed under the 2020 Credit Facility with the margin now fixed at 4.5%. In conjunction with the Sixth Amendment, the Company made a $75 million prepayment that was applied to the final payment due upon maturity in March 2025 of approximately $200.4 million. The $75 million prepayment was almost entirely funded with the net proceeds from the Private Placement and the sales of our interest rate swap. Debt issuance costs associated with the Sixth Amendment totaled $1.7 million and are being amortized on a straight-line basis over the remaining life of the 2020 Credit Facility to Interest expense, net. The Company's interest rates under the 2020 Term Loan for the three months ended March 31, 2023 benefited from a hedge instrument that was in place, specifically a fixed rate swap, which was sold in March 2023 (see Note 10). As a result of the fixed rate swap sold in March 2023, the ongoing interest rate is based upon U.S. dollar SOFR plus a fixed margin of 4.5%. The Company was in compliance with all covenants of the 2020 Credit Facility at both March 31, 2024 and December 31, 2023, including the current Consolidated Net Leverage Ratio calculation that considers the Company's debt to include Preferred Stock. The Company had the following outstanding borrowings, unamortized debt issuance costs, letters of credit, interest rates, and remaining borrowing capacity under the 2020 Credit Facility as of March 31, 2024 and December 31, 2023:   March 31, 2024 December 31, 2023 Current portion of Term Debt $ 228,168 $ 35,102 Long-term Debt, net of Current: Long-term Debt, net of Current (Face Amount) $ — $ 200,293 Unamortized Debt Issuance Costs - Contra-Liability — (2,811) Long-term Debt, net of Current $ — $ 197,482 Total Face Amount of Borrowings $ 230,381 $ 235,395 Unamortized Debt Issuance Costs: Other Assets $ 439 $ 557 Current Portion of Term Debt - Contra Liability 2,213 — Long-Term Debt - Contra Liability — 2,811 Total Unamortized Debt Issuance Costs $ 2,652 $ 3,368 Letters of Credit Outstanding $ 2,711 $ 2,711 Remaining Borrowing Capacity $ 72,289 $ 72,289 Average Interest Rates: Term Loan 9.9  % 10.0  % Letters of Credit 4.5  % 4.5  % The Company's debt maturities as of March 31, 2024 were as follows: Years ending December 31, Remainder of 2024 $ 30,087  2025 200,294  $ 230,381  Letters of Credit and Other Guarantees The Company uses letters of credit and performance and bid bonds in the course of its business. At March 31, 2024, the Company had $9.7 million of letters of credit, bank guarantees, and performance and bid bonds outstanding (collectively, "Guarantees"), comprised of the $2.7 million of letters of credit under the 2020 Credit Facility described above (the "Letters of Credit") and $7.0 million of bank guarantees and performance and bid bonds (collectively, the "Other Guarantees") under various uncommitted facilities. At December 31, 2023, the Company had Guarantees aggregating $7.9 million, comprised of the $2.7 million of Letters of Credit noted above and $5.2 million of Other Guarantees.

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DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	3 Months Ended
	Mar. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Company is exposed to financial market risk related to foreign currency fluctuations and changes in interest rates. These exposures are actively monitored by management. To manage the volatility related to the exposure to changes in interest rates, the Company may enter into derivative financial instruments. Management's objective has been to reduce, where it is deemed appropriate to do so, fluctuations in earnings and cash flows associated with changes in interest rates. Ribbon's policies and practices are to use derivative financial instruments only to the extent necessary to manage exposures. Ribbon does not hold or issue derivative financial instruments for trading or speculative purposes. The Company records derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a specific risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Derivatives may also be designated as hedges of the foreign currency exposure of a net investment in a foreign operation. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge, or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk even though hedge accounting does not apply or the Company elects not to apply hedge accounting. Cash Flow Hedge of Interest Rate Risk The 2020 Term Loan Facility had outstanding balances of $230.4 million and $235.4 million at March 31, 2024 and December 31, 2023, respectively. The 2020 Revolving Credit Facility was undrawn at March 31, 2024 and December 31, 2023. Borrowings under the 2020 Credit Facility have variable interest rates based on LIBOR or SOFR (see Note 9). As a result of exposure to interest rate movements, during March 2020, the Company entered into an interest rate swap arrangement, which effectively converted its $400 million term loan with its variable interest rate based upon one-month LIBOR to an aggregate fixed rate of 0.904%, plus a leverage-based margin as defined in the 2020 Credit Facility. On July 22, 2022, the Company sold $30 million of the notional amount of its interest rate swap back to its counterparty for $1.5 million, reducing the notional amount of this swap to $370 million. On August 16, 2022 the Company sold another $30 million of the notional amount of its interest rate swap back to its counterparty for $1.6 million, reducing the notional amount to $340 million, which approximated the current level of our term loan debt then outstanding. The gain in accumulated other comprehensive (loss) income related to the $60 million notional amount sold of $3.1 million is being released into earnings on a straight line basis over the remaining term of the 2020 Credit Facility as a decrease to interest expense, the amortization of which totaled $0.2 million and $0.3 million for the three months ended March 31, 2024 and 2023, respectively. On March 24, 2023, the Company received $9.4 million, consisting of $0.4 million of interest and $9.0 million for the sale of $170 million of its $340 million notional amount interest rate swap back to its counterparty, reducing the notional amount to $170 million. On March 27, 2023, the Company received $9.8 million, consisting of $0.4 million of interest and $9.4 million for the sale of the remaining $170 million of its interest rate swap back to its counterparty. The portion of the gain in accumulated other comprehensive (loss) income related to the term loan debt prepaid on the date of the final sale of our swap totaled $7.3 million and was released into earnings immediately as Other expense, net. The portion of the gain in accumulated other comprehensive (loss) income related to our remaining term loan debt balance was $12.0 million and is being released into earnings on a straight line basis over the remaining term of the 2020 Credit Facility as a decrease to interest expense, the amortization of which totaled $1.6 million for the three months ended March 31, 2024. The Company’s objectives in using interest rate derivatives have been to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company has used an interest rate swap as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the related agreements without exchange of the underlying notional amount. The effective portion of changes in the fair value of designated derivatives that qualify as cash flow hedges is recorded in accumulated other comprehensive income in the condensed consolidated balance sheet and is subsequently reclassified into earnings in the period that the hedged forecasted transactions affect earnings. During the three months ended March 31, 2023, such a derivative was used to hedge the variable cash flows associated with the outstanding borrowings under the 2020 Credit Facility and the Company has accounted for this derivative as an effective hedge until the final portion of the swap was sold on March 27, 2023. Any ineffective portion of the change in the fair value of the derivative was recognized directly in earnings. Amounts reported in accumulated other comprehensive income related to the Company's derivative are reclassified to interest expense as interest is accrued on the Company’s variable-rate debt. The impact of the Company’s derivative financial instrument on its condensed consolidated statements of comprehensive (loss) income for the three months ended March 31, 2024 and 2023 was as follows, net of tax (in thousands): Three months ended   March 31, 2024 March 31, 2023 Gain (loss) recognized in other comprehensive income (loss) on swap, net of tax $ —  $ (2,715) Amount reclassified from accumulated other comprehensive income to other expense, net upon sale of swap, net of tax —  (5,099) Amount reclassified from accumulated other comprehensive income to interest expense (1,321) (3,185) Unrealized gain (loss) on interest rate swap, net of reclassifications and amortization $ (1,321) $ (10,999) The Company had no derivative assets or liabilities at March 31, 2024 or December 31, 2023.

v3.24.1.1.u2

PREFERRED STOCK AND WARRANTS	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
PREFERRED STOCK AND WARRANTS	PREFERRED STOCK AND WARRANTS On March 28, 2023, the Company issued 55,000 shares of Preferred Stock to investors in the Private Placement at a price of $970 per share, along with 4,858,090 Warrants with an exercise price of $3.77 per share. The Company accounts for the Preferred Stock and Warrants as liability-classified instruments based on an assessment of their specific terms in accordance with ASC Topic 480, Distinguishing Liabilities from Equity. The fair value option was elected for the Preferred Stock, as the Company considers fair value to best reflect its expected future economic value. These liabilities are remeasured to fair value at each reporting date using the same valuation methodology applied upon issuance using current input assumptions. The value of the Preferred Stock is calculated using the Black-Derman-Toy (BDT) stochastic yield lattice model to capture the optimal timing of repayment, increasing dividend rate and other features and the value of the Warrants is calculated using the Black-Scholes Pricing Model. Changes in the fair value of the Preferred Stock and Warrants are reported as Other expense, net in the Company's condensed consolidated statements of operations. The Company determined the fair value of the Preferred Stock and Warrants using Level 3 input. The key assumptions into the models utilized were as follows as of March 31, 2024: Preferred Stock (BDT) Face value per share $1,000 Interest payments per year 4 Dividend rate - year 1 (paid in-kind) 9.25% Dividend rate - year 2 (paid in-kind or in cash at the Company's choice) 9.75% Dividend rate - thereafter (paid in cash) 12.00% Yield volatility 25.0% Time to maturity (in years) 1.5 Warrants (Black-Scholes) Stock price $3.20 Strike price $3.77 Risk-free rate 4.35% Volatility 59.2% Dividend yield 0.0% Time to expiration (years) 3.0 The changes in the Company's Preferred Stock and Warrant liabilities the three months ended March 31, 2024 were as follows (in thousands): Preferred stock liability Balance at January 1, 2024 $ 53,337  Payable in-kind dividends 1,355  Fair value change 1,512  Balance at March 31, 2024 $ 56,204  Warrant liability Balance at January 1, 2024 $ 5,295  Fair value change 632  Balance at March 31, 2024 $ 5,927  The Preferred Stock is subordinate to Company indebtedness and senior to the Company’s common stock or other equity. Holders of the Preferred Stock are entitled to cumulative dividends that accrue quarterly through the September 30, 2025 maturity date. Dividends are payable in-kind during the first year at a rate of 9.25%. At the Company’s option, the dividends are payable in-kind or in cash during the second year at a rate of 9.75%. Dividends thereafter are payable in cash at a rate of 12.00%. The proceeds from the Preferred Stock issuance were approximately $53.4 million, including $10.0 million from existing related party stockholders. Offering costs paid by the Company of approximately $3.5 million were recorded in Other expense, net in the year ended December 31, 2023. The net proceeds from the Private Placement were used for the repayment of debt. The Preferred Stock is redeemable on or after the first and second anniversaries of the closing date at a rate of 103% and 102%, respectively. The Warrants, which expire March 30, 2027, are immediately exercisable and upon an event such as a merger, consolidation, asset sale or similar change of control, may be exercised and the holders may vote the underlying shares of common stock. In connection with the Private Placement, the Company provided the investors with certain registration rights relating to the Preferred Stock, the Warrants and the shares of the Company’s common stock underlying the Warrants, that required the Company to file a registration statement on Form S-3 with the SEC within 30 days following the closing date of the Private Placement. The registration requirement was completed on May 19, 2023.

v3.24.1.1.u2

REVENUE RECOGNITION	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION The Company derives revenue from two primary sources: products and services. Product revenue includes the Company's hardware and software that function together to deliver the products' essential functionality. Software and hardware are also sold on a standalone basis. Services include customer support (software updates, upgrades and technical support), consulting, design services, installation services and training. Generally, contracts with customers contain multiple performance obligations, consisting of products and services. For these contracts, the Company accounts for individual performance obligations separately if they are considered distinct. When an arrangement contains more than one performance obligation, the Company will allocate the transaction price to each performance obligation on a relative standalone selling price basis. The Company utilizes the observable price of goods and services when they are sold separately to similar customers in order to estimate standalone selling price. The Company's software licenses typically provide a perpetual right to use the Company's software. The Company also sells term-based software licenses that expire and Software-as-a-Service ("SaaS")-based software which are referred to as subscription arrangements. The Company does not customize its software nor are installation services required, as the customer has a right to utilize internal resources or a third-party service company. The software and hardware are delivered before related services are provided and are functional without professional services or customer support. The Company has concluded that its software licenses are functional intellectual property that are distinct, as the user can benefit from the software on its own. Product revenue is typically recognized upon transfer of control or when the software is made available for download, as this is the point the user of the software can direct the use of, and obtain substantially all of the remaining benefits from, the functional intellectual property. The Company begins to recognize software revenue related to the renewal of subscription software licenses at the start of the subscription period. The Company offers warranties on its products. Certain of the Company's warranties are considered to be assurance-type in nature, ensuring the product is functioning as intended. Assurance-type warranties do not represent separate performance obligations. The Company also sells separately-priced maintenance service contracts which qualify as service-type warranties and represent separate performance obligations. The Company does not allow and has no history of accepting product returns. Services revenue includes revenue from customer support and other professional services. Customer support includes software updates on a when-and-if-available basis, telephone support, integrated web-based support and bug fixes or patches. The Company sells its customer support contracts at a percentage of list or net product price. Customer support revenue is recognized ratably over the term of the customer support agreement, which is typically one year. The Company's professional services include consulting, technical support, resident engineer services, design services and installation services. Because control transfers over time, revenue is recognized based on progress toward completion of the performance obligation. The method to measure progress toward completion requires judgment and is based on the nature of the products or services to be provided. The Company generally uses the input method to measure progress for its contracts because it believes such method best depicts the transfer of assets to the customer, which occurs as the Company incurs costs for the contracts. However, in some instances, the Company uses the output method because it best depicts the transfer of asset to the customer. Under the cost-to-cost measure of progress, the progress toward completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. When the measure of progress is based upon expended labor, progress toward completion is measured as the ratio of labor time expended to date versus the total estimated labor time required to complete the performance obligation. Revenue is recorded proportionally as costs are incurred or as labor is expended. Costs to fulfill these obligations include internal labor as well as subcontractor costs. Customer training includes courses offered by the Company. The related revenue is typically recognized as the training services are performed. The Company's typical performance obligations include the following: Performance Obligation When Performance Obligation is Typically Satisfied When Payment is Typically Due Software and Product Revenue Software licenses (perpetual or term) Upon transfer of control; typically, when made available for download (point in time) Generally, within 30 days of invoicing except for term licenses, which may be paid for over time Software licenses (subscription) Upon activation of hosted site (over time) Generally, within 30 days of invoicing Hardware When control of the hardware passes to the customer; typically, upon delivery (point in time) Generally, within 30 days of invoicing Software upgrades Upon transfer of control; typically, when made available for download (point in time) Generally, within 30 days of invoicing Customer Support Revenue Customer support Ratably over the course of the support contract (over time) Generally, within 30 days of invoicing Professional Services Other professional services (excluding training services) As work is performed (over time) Generally, within 30 days of invoicing (upon completion of services) Training When the class is taught (point in time) Generally, within 30 days of services being performed Significant Judgments The Company's contracts with customers often include promises to transfer multiple products and services to the customer. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment. Judgment is required to determine the standalone selling price ("SSP") for each distinct performance obligation. The Company typically has more than one SSP for individual products and services due to the stratification of those products and services by customers and circumstances. In these instances, the Company may use information such as the size of the customer and geographic region in determining the SSP. Deferred Revenue Deferred revenue is a contract liability representing amounts collected from or invoiced to customers in excess of revenue recognized. This results primarily from the billing of annual customer support agreements where the revenue is recognized over the term of the agreement. The value of deferred revenue will increase or decrease based on the timing of recognition of revenue. Disaggregation of Revenue The Company disaggregates its revenue from contracts with customers based on the nature of the products and services and the geographic regions in which each customer is domiciled. The Company's revenue for the three months ended March 31, 2024 and 2023 was disaggregated as follows: Three months ended March 31, 2024 Product revenue Service revenue (maintenance) Service revenue (professional services) Total revenue United States $ 26,607  $ 32,847  $ 11,660  $ 71,114  Europe, Middle East and Africa 41,689  17,696  7,698  67,083  Asia Pacific 16,633  10,241  2,927  29,801  Other 2,681  7,597  1,388  11,666  $ 87,610  $ 68,381  $ 23,673  $ 179,664  Three months ended March 31, 2023 Product revenue Service revenue (maintenance) Service revenue (professional services) Total revenue United States $ 38,067  $ 33,073  $ 10,853  $ 81,993  Europe, Middle East and Africa 27,435  20,127  6,575  54,137  Asia Pacific 25,615  9,372  3,144  38,131  Other 2,201  8,016  1,681  11,898  $ 93,318  $ 70,588  $ 22,253  $ 186,159  The Company's product revenue from indirect sales through its channel partner program and from its direct sales program for the three months ended March 31, 2024 and 2023 was as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Indirect sales through channel partner program $ 45,675  $ 35,914  Direct sales 41,935  57,404  $ 87,610  $ 93,318  The Company's product revenue from sales to enterprise customers and from sales to service provider customers for the three months ended March 31, 2024 and 2023 was as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Sales to enterprise customers $ 37,870  $ 27,412  Sales to service provider customers 49,740  65,906  $ 87,610  $ 93,318  The Company's product revenue and service revenue components by segment for the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Product revenue:   Cloud and Edge $ 31,513  $ 42,839    IP Optical Networks 56,097  50,479      Total product revenue $ 87,610  $ 93,318  Service revenue:   Maintenance:     Cloud and Edge $ 53,196  $ 54,810      IP Optical Networks 15,185  15,778        Total maintenance revenue 68,381  70,588    Professional services:     Cloud and Edge 16,960  16,831      IP Optical Networks 6,713  5,422        Total professional services revenue 23,673  22,253          Total service revenue $ 92,054  $ 92,841  Revenue Contract Balances The timing of revenue recognition, billings and cash collections results in billed accounts receivable; unbilled receivables, which are contract assets; and customer advances and deposits, which are contract liabilities, in the Company's condensed consolidated balance sheets. Amounts are billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Completion of services and billing may occur subsequent to revenue recognition, resulting in contract assets. The Company may receive advances or deposits from its customers before revenue is recognized, resulting in contract liabilities that are classified as deferred revenue. These assets and liabilities are reported in the Company's condensed consolidated balance sheets on a contract-by-contract basis as of the end of each reporting period. Changes in the contract asset and liability balances during the three months ended March 31, 2024 were not materially impacted by any factors other than billing and revenue recognition. Nearly all of the Company's deferred revenue balance is related to services revenue, primarily customer support contracts. Unbilled receivables stem primarily from engagements where services have been performed; however, billing cannot occur until services are completed. In some arrangements, the Company allows customers to pay for term-based software licenses and products over the term of the software license. The Company also sells SaaS-based software under subscription arrangements, with payment terms over the term of the SaaS agreement. Amounts recognized as revenue in excess of amounts billed are recorded as unbilled receivables. Unbilled receivables that are anticipated to be invoiced in the next twelve months are included in Accounts receivable on the Company's condensed consolidated balance sheets. The changes in the Company's accounts receivable, unbilled receivables and deferred revenue balances for the three months ended March 31, 2024 were as follows (in thousands): Accounts receivable Unbilled accounts receivable Deferred revenue (current) Deferred revenue (long-term) Balance at January 1, 2024 $ 186,938  $ 81,483  $ 113,381  $ 19,218  Increase (decrease), net (43,634) (12,289) (2,785) (5,199) Balance at March 31, 2024 $ 143,304  $ 69,194  $ 110,596  $ 14,019  The Company recognized approximately $51 million of revenue in the three months ended March 31, 2024 that was recorded as deferred revenue at December 31, 2023 and approximately $48 million of revenue in the three months ended March 31, 2023 that was recorded as deferred revenue at December 31, 2022. Of the Company's deferred revenue reported as long-term in its condensed consolidated balance sheet at March 31, 2024, the Company expects that approximately $7 million will be recognized as revenue in 2025, approximately $4 million will be recognized as revenue in 2026 and approximately $3 million will be recognized as revenue in 2027 and beyond. All freight-related customer invoicing is recorded as revenue, while the shipping and handling costs that occur after control of the promised goods or services transfer to the customer are reported as fulfillment costs, a component of Cost of revenue - product in the Company's condensed consolidated statements of operations. Deferred Commissions Cost Sales commissions earned by the Company's employees are considered incremental and recoverable costs of obtaining a contract with a customer. These costs have been deferred on our condensed consolidated balance sheet and are being amortized over the expected life of the customer contract, which is generally five years. At both March 31, 2024 and December 31, 2023, the Company had $3.0 million of deferred sales commissions capitalized.

v3.24.1.1.u2

OPERATING SEGMENT INFORMATION	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
OPERATING SEGMENT INFORMATION	OPERATING SEGMENT INFORMATION The Company has two reportable segments, which are intended to align with the manner in which the business is managed: Cloud and Edge, and IP Optical Networks. The Cloud and Edge segment provides secure and reliable software and hardware products, solutions and services for enabling Voice over Internet Protocol ("VoIP") communications, Voice over Long-Term Evolution ("VoLTE") and Voice Over 5G ("VoNR") communications, and Unified Communications and Collaboration ("UC&C") within service provider and enterprise networks and from the cloud. The Cloud and Edge products are increasingly software-centric and cloud-native for deployment on private, public or hybrid cloud infrastructures, in data centers, on enterprise premises and within service provider networks. Ribbon's Cloud and Edge product portfolio consists primarily of its Session Border Controller ("SBC") products and its Network Transformation products. The IP Optical Networks segment provides high-performance, secure solutions for IP networking and optical transport, supporting wireless networks including 5G, metro and edge aggregation, core networking, data center interconnect, legacy transformation and transport solutions for wholesale carriers. This portfolio is offered to service provider, enterprise and industry verticals with critical transport network infrastructures including utilities, government, defense, transportation, and education and research. The Company has not provided segment asset information as such information is not provided to the CODM and accordingly, asset information is not used in assessing segment performance. Segment revenue and expenses included in the tables below represent direct revenue and expense attributable to each segment. Please see Note 4 for information regarding the allocation of goodwill between segments. The CODM utilizes revenue and adjusted gross profit to measure and assess each segment's performance. The Company calculates adjusted gross profit by excluding from cost of revenue: amortization of acquired technology, stock-based compensation, and may also exclude other items in future periods that the Company believes are not part of the Company's core business. Adjusted gross profit is not a financial measure determined in accordance with U.S. GAAP, may not be comparable to similarly titled measures used by other companies, and should not be considered a substitute for gross profit or other results reported in accordance with U.S. GAAP. See below for a reconciliation of adjusted gross profit to gross profit which is the most directly comparable U.S. GAAP measure. The tables below provide revenue, adjusted gross profit and depreciation expense by reportable segment for the three months ended March 31, 2024 and 2023 (in thousands): Three months ended March 31, 2024 March 31, 2023 Segment revenue:   Cloud and Edge $ 101,669  $ 114,480    IP Optical Networks 77,995  71,679      Revenue $ 179,664  $ 186,159  Three months ended March 31, 2024 March 31, 2023 Segment adjusted gross profit:   Cloud and Edge $ 67,119  $ 69,975    IP Optical Networks 31,965  19,500      Total segment adjusted gross profit 99,084  89,475  Stock-based compensation expense (578) (684) Amortization of acquired technology (6,551) (7,389)       Gross profit $ 91,955  $ 81,402  Three months ended March 31, 2024 March 31, 2023 Segment depreciation expense:   Cloud and Edge $ 2,333  $ 2,499    IP Optical Networks 1,061  1,011      Depreciation expense $ 3,394  $ 3,510

v3.24.1.1.u2

MAJOR CUSTOMERS	3 Months Ended
	Mar. 31, 2024
Risks and Uncertainties [Abstract]
MAJOR CUSTOMERS	MAJOR CUSTOMERS The following customer contributed 10% or more of the Company's revenue in the three months ended March 31, 2024 and 2023:   Three months ended   March 31, 2024 March 31, 2023 Verizon Communications Inc. * 11% * Less than 10% of total revenue. At March 31, 2024 and December 31, 2023, no customer accounted for 10% or more of the Company's accounts receivable balance. The Company performs ongoing credit evaluations of its customers and generally does not require collateral on accounts receivable. The Company maintains an allowance for doubtful accounts and such losses have historically been within management's expectations.

v3.24.1.1.u2

STOCK-BASED COMPENSATION PLANS	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION PLANS	STOCK-BASED COMPENSATION PLANS The Company grants stock-based compensation to employees, officers and non-employee directors, as well as consultants and advisors of the Company and its subsidiaries under its Amended and Restated 2019 Incentive Award Plan which provides for the award of stock options, stock appreciation rights, restricted stock awards ("RSAs"), performance-based stock awards, restricted stock units ("RSUs"), performance-based stock units ("PSUs") and other stock- or cash-based awards. Executive Equity Arrangements Inducement Awards In connection with his appointment as President and Chief Executive Officer of Ribbon on March 16, 2020, the Company awarded Bruce McClelland sign-on equity grants, comprised of RSUs and a PSU grant with both market and service conditions. As of March 31, 2024, the Company estimates that the market conditions surrounding the PSUs granted will not be met by the expiration date of September 1, 2024. Performance-Based Stock Grants In addition to granting RSAs and RSUs to its executives and certain of its employees, the Company also grants PSUs to certain of its executives and certain other employees. Vesting periods for RSAs, RSUs, and PSUs granted range from one to three years. PSUs granted consist of 60% that have both performance and service conditions (the "Performance PSUs") and 40% that have both market and service conditions (the "Market PSUs"). Each Performance PSU is comprised of three consecutive fiscal year performance periods beginning in the year of grant, with one-third of the Performance PSUs attributable to each fiscal year performance period. The Market PSUs have one three-year performance period, beginning January 1 in the year of grant and ending on December 31, three years thereafter. The number of shares of common stock underlying the PSUs that can be earned will not exceed 200% of the Performance or Market PSUs. Shares subject to PSUs that fail to be earned will be forfeited. Restricted Stock Units The activity related to the Company's RSUs for the three months ended March 31, 2024 was as follows: Shares Weighted Average Grant Date Fair Value Unvested balance at January 1, 2024 7,091,368  $ 3.18  Granted 29,366  $ 2.89  Vested (888,189) $ 5.05  Forfeited (200,229) $ 3.26  Unvested balance at March 31, 2024 6,032,316  $ 2.90  The total grant date fair value of shares of restricted stock underlying RSUs that vested during the three months ended March 31, 2024 was $4.5 million. Performance-Based Stock Units The activity related to the Company's PSUs for the three months ended March 31, 2024 was as follows: Shares Weighted Average Grant Date Fair Value Unvested balance at January 1, 2024 6,297,931  $ 2.07  Granted —  $ —  Vested (31,282) $ 6.40  Forfeited (280,304) $ 9.40  Unvested balance at March 31, 2024 5,986,345  $ 1.70  The total grant date fair value of shares of restricted stock underlying PSUs that vested during the three months ended March 31, 2024 was $0.2 million. Stock-Based Compensation The condensed consolidated statements of operations include stock-based compensation for the three months ended March 31, 2024 and 2023 as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Product cost of revenue $ 106  $ 149  Service cost of revenue 472  535  Research and development 1,068  1,262  Sales and marketing 1,157  2,129  General and administrative 1,719  1,773  $ 4,522  $ 5,848  At March 31, 2024, there was $13.4 million, net of expected forfeitures, of unrecognized stock-based compensation expense related to unvested RSUs and PSUs. This expense is expected to be recognized over a weighted average period of approximately one year.

v3.24.1.1.u2

LEASES	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
LEASES	LEASES The Company has operating leases for corporate offices and research and development facilities and has historically had finance leases for certain equipment. Operating leases are reported separately in the Company's condensed consolidated balance sheets. Assets acquired under finance leases, if any, are included in Property and equipment, net, in the condensed consolidated balance sheets. The Company determines if an arrangement is a lease at inception. A contract is determined to contain a lease component if the arrangement provides the Company with a right to control the use of an identified asset. Lease agreements may include lease and non-lease components. In such instances for all classes of underlying assets, the Company does not separate lease and non-lease components but rather, accounts for the entire arrangement under leasing guidance. Leases with an initial term of 12 months or less are not recorded on the balance sheet and lease expense for these leases is recognized on a straight-line basis over the lease term. Right-of-use assets and lease liabilities are initially measured based on the present value of the future minimum fixed lease payments (i.e., fixed payments in the lease contract) over the lease term at the commencement date. As the Company's existing leases do not have a readily determinable implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of future minimum fixed lease payments. The Company calculates its incremental borrowing rate to reflect the interest rate that it would have to pay to borrow on a collateralized basis an amount equal to the lease payments in a similar economic environment over a similar term and considers its historical borrowing activities and market data from entities with comparable credit ratings in this determination. The measurement of the right-of-use asset also includes any lease payments made prior to the commencement date (excluding any lease incentives) and initial direct costs incurred. The Company assessed its right-of-use assets for impairment as of March 31, 2024 and December 31, 2023 and determined no impairment has occurred. Lease terms may include options to extend or terminate the lease and the Company incorporates such options in the lease term when it has the unilateral right to make such an election and it is reasonably certain that the Company will exercise that option. In making this determination, the Company considers its prior renewal and termination history and planned usage of the assets under lease, incorporating expected market conditions. For operating leases, lease expense for minimum fixed lease payments is recognized on a straight-line basis over the lease term. The expense for finance leases includes both interest and amortization expense components, with the interest component calculated based on the effective interest method and the amortization component calculated based on straight-line amortization of the right-of-use asset over the lease term. Lease contracts may contain variable lease costs, such as common area maintenance, utilities and tax reimbursements that vary over the term of the contract. Variable lease costs are not included in minimum fixed lease payments and as a result, are excluded from the measurement of the right-of-use assets and lease liabilities. The Company expenses all variable lease costs as incurred. Certain leased facilities are being partially or fully vacated as part of the 2022 Restructuring Plan and for some of those facilities, the Company has no plans to enter into sublease agreements. Accordingly, the Company accelerated the amortization of those lease assets through the planned cease-use date of each facility, resulting in additional amortization expense $0.2 million in the three months ended March 31, 2023. No such accelerated amortization was recorded in the three months ended March 31, 2024. The Company did not record estimated future variable lease costs in the three months ended March 31, 2024 or 2023 related to the 2022 Restructuring Plan. All incremental accelerated amortization and accruals for estimated future variable costs are included in Restructuring and related expense in the Company's condensed consolidated statements of operations. At March 31, 2024 and December 31, 2023, the Company had accruals of $1.4 million and $1.5 million, respectively, for all future anticipated variable lease costs related to these facilities. The Company may incur additional future expense if it is unable to sublease other locations included in the Facilities Initiative. The Company leases its corporate offices and other facilities under operating leases, which expire at various times through 2033. The Company's right-of-use lease assets and lease liabilities at March 31, 2024 and December 31, 2023 were as follows (in thousands): Classification March 31, 2024 December 31, 2023 Assets:   Operating lease assets Operating lease right-of-use assets $ 37,110  $ 39,783  Liabilities:     Current Operating Operating lease liabilities $ 14,213  $ 15,739      Non-Current Operating Operating lease liabilities, net of current 36,768  38,711        Total Operating lease liabilities $ 50,981  $ 54,450  The components of lease expense for the three months ended March 31, 2024 and 2023 were as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Operating lease cost* $ 4,199  $ 4,760  Short-term lease cost 3,441  3,427  Variable lease costs (costs excluded from minimum fixed lease payments)** 855  802  Sublease income (260) (430)     Net lease cost $ 8,235  $ 8,559  * No accelerated amortization was recorded in the three months ended March 31, 2024. Operating lease costs for the three months ended March 31, 2023 included $0.2 million of accelerated amortization for certain assets partially or fully vacated with no intent or ability to sublease. ** No variable lease costs were accrued in the three months ended March 31, 2024 or 2023 for future estimated variable expenses related to certain assets partially or fully vacated with no intent or ability to sublease. Cash flows related to the Company's leases in both the three months ended March 31, 2024 and 2023 were included in the measurement of operating lease liabilities and classified as operating cash flows and each totaled $4.8 million. Other information related to the Company's leases as of March 31, 2024 and December 31, 2023 was as follows:   March 31, 2024 December 31, 2023 Weighted average remaining lease term (years):   Operating leases 5.45 5.50 Weighted average discount rate:   Operating leases 7.04  % 6.34  % Future minimum fixed lease payments under noncancelable leases at March 31, 2024 were as follows (in thousands):   Operating leases Remainder of 2024 $ 13,873  2025 10,799  2026 9,018  2027 7,857  2028 6,452  2029 13,161    Total lease payments 61,160    Less: interest (10,179)     Present value of lease liabilities $ 50,981
LEASES	LEASES The Company has operating leases for corporate offices and research and development facilities and has historically had finance leases for certain equipment. Operating leases are reported separately in the Company's condensed consolidated balance sheets. Assets acquired under finance leases, if any, are included in Property and equipment, net, in the condensed consolidated balance sheets. The Company determines if an arrangement is a lease at inception. A contract is determined to contain a lease component if the arrangement provides the Company with a right to control the use of an identified asset. Lease agreements may include lease and non-lease components. In such instances for all classes of underlying assets, the Company does not separate lease and non-lease components but rather, accounts for the entire arrangement under leasing guidance. Leases with an initial term of 12 months or less are not recorded on the balance sheet and lease expense for these leases is recognized on a straight-line basis over the lease term. Right-of-use assets and lease liabilities are initially measured based on the present value of the future minimum fixed lease payments (i.e., fixed payments in the lease contract) over the lease term at the commencement date. As the Company's existing leases do not have a readily determinable implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of future minimum fixed lease payments. The Company calculates its incremental borrowing rate to reflect the interest rate that it would have to pay to borrow on a collateralized basis an amount equal to the lease payments in a similar economic environment over a similar term and considers its historical borrowing activities and market data from entities with comparable credit ratings in this determination. The measurement of the right-of-use asset also includes any lease payments made prior to the commencement date (excluding any lease incentives) and initial direct costs incurred. The Company assessed its right-of-use assets for impairment as of March 31, 2024 and December 31, 2023 and determined no impairment has occurred. Lease terms may include options to extend or terminate the lease and the Company incorporates such options in the lease term when it has the unilateral right to make such an election and it is reasonably certain that the Company will exercise that option. In making this determination, the Company considers its prior renewal and termination history and planned usage of the assets under lease, incorporating expected market conditions. For operating leases, lease expense for minimum fixed lease payments is recognized on a straight-line basis over the lease term. The expense for finance leases includes both interest and amortization expense components, with the interest component calculated based on the effective interest method and the amortization component calculated based on straight-line amortization of the right-of-use asset over the lease term. Lease contracts may contain variable lease costs, such as common area maintenance, utilities and tax reimbursements that vary over the term of the contract. Variable lease costs are not included in minimum fixed lease payments and as a result, are excluded from the measurement of the right-of-use assets and lease liabilities. The Company expenses all variable lease costs as incurred. Certain leased facilities are being partially or fully vacated as part of the 2022 Restructuring Plan and for some of those facilities, the Company has no plans to enter into sublease agreements. Accordingly, the Company accelerated the amortization of those lease assets through the planned cease-use date of each facility, resulting in additional amortization expense $0.2 million in the three months ended March 31, 2023. No such accelerated amortization was recorded in the three months ended March 31, 2024. The Company did not record estimated future variable lease costs in the three months ended March 31, 2024 or 2023 related to the 2022 Restructuring Plan. All incremental accelerated amortization and accruals for estimated future variable costs are included in Restructuring and related expense in the Company's condensed consolidated statements of operations. At March 31, 2024 and December 31, 2023, the Company had accruals of $1.4 million and $1.5 million, respectively, for all future anticipated variable lease costs related to these facilities. The Company may incur additional future expense if it is unable to sublease other locations included in the Facilities Initiative. The Company leases its corporate offices and other facilities under operating leases, which expire at various times through 2033. The Company's right-of-use lease assets and lease liabilities at March 31, 2024 and December 31, 2023 were as follows (in thousands): Classification March 31, 2024 December 31, 2023 Assets:   Operating lease assets Operating lease right-of-use assets $ 37,110  $ 39,783  Liabilities:     Current Operating Operating lease liabilities $ 14,213  $ 15,739      Non-Current Operating Operating lease liabilities, net of current 36,768  38,711        Total Operating lease liabilities $ 50,981  $ 54,450  The components of lease expense for the three months ended March 31, 2024 and 2023 were as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Operating lease cost* $ 4,199  $ 4,760  Short-term lease cost 3,441  3,427  Variable lease costs (costs excluded from minimum fixed lease payments)** 855  802  Sublease income (260) (430)     Net lease cost $ 8,235  $ 8,559  * No accelerated amortization was recorded in the three months ended March 31, 2024. Operating lease costs for the three months ended March 31, 2023 included $0.2 million of accelerated amortization for certain assets partially or fully vacated with no intent or ability to sublease. ** No variable lease costs were accrued in the three months ended March 31, 2024 or 2023 for future estimated variable expenses related to certain assets partially or fully vacated with no intent or ability to sublease. Cash flows related to the Company's leases in both the three months ended March 31, 2024 and 2023 were included in the measurement of operating lease liabilities and classified as operating cash flows and each totaled $4.8 million. Other information related to the Company's leases as of March 31, 2024 and December 31, 2023 was as follows:   March 31, 2024 December 31, 2023 Weighted average remaining lease term (years):   Operating leases 5.45 5.50 Weighted average discount rate:   Operating leases 7.04  % 6.34  % Future minimum fixed lease payments under noncancelable leases at March 31, 2024 were as follows (in thousands):   Operating leases Remainder of 2024 $ 13,873  2025 10,799  2026 9,018  2027 7,857  2028 6,452  2029 13,161    Total lease payments 61,160    Less: interest (10,179)     Present value of lease liabilities $ 50,981

v3.24.1.1.u2

INCOME TAXES	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company recorded income tax provisions of $3.4 million and $1.5 million in the three months ended March 31, 2024 and 2023, respectively. These amounts reflect the Company's estimates of the effective rates expected to be applicable for the respective full years, adjusted for any discrete events, which are recorded in the period in which they occur. These estimates are reevaluated each quarter based on the Company's estimated tax expense for the full fiscal year. The estimated effective tax rate includes the impact of valuation allowances in various jurisdictions. The Company intends to continue to maintain a valuation allowance on its deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of the respective allowances.

v3.24.1.1.u2

RELATED PARTIES	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
RELATED PARTIES	RELATED PARTIES The Company recognized revenue from its largest stockholder of $1.5 million and $0.8 million in the three months ended March 31, 2024 and 2023, respectively. Additionally, as discussed in Note 11, certain related party stockholders participated in the Private Placement.

v3.24.1.1.u2

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Liabilities for Royalty Payments to the IIA Prior to the Company's acquisition of ECI Telecom Group Ltd. ("ECI"), ECI had received research and development grants from the Office of the Innovation Authority of the Israeli Ministry of Economics (the "IIA"). The Company assumed ECI's contract with the IIA, which requires the Company to pay royalties to the IIA on proceeds from the sale of products which the Israeli government has supported by way of research and development grants. The royalties for grants prior to 2017 were calculated at the rates of 1.3% to 5.0% of the aggregated proceeds from the sale of such products developed at certain of the Company's R&D centers, up to an amount not exceeding 100% of such grants plus interest at LIBOR. Effective for grants approved in 2017 and subsequently, interest was calculated at the higher of LIBOR plus 1.5% to 2.75%. At March 31, 2024, the Company's maximum possible future royalties commitment, including $1.8 million of unpaid royalties accrued, was $20.6 million, including interest of $1.1 million, based on estimates of future product sales, grants received from the IIA not yet repaid, and management's estimation of products still to be sold. Litigation The Company is often a party to disputes and legal proceedings that it considers routine and incidental to its business, including those described below. The Company believes that it has meritorious defenses to the allegations made in the pending cases and intends to vigorously defend these lawsuits; however, the Company is unable currently to forecast the ultimate outcome of these or similar matters. Since it is difficult to predict the outcome of legal proceedings, it is possible that the ultimate outcomes could materially and adversely affect the Company’s business, financial position, results of operations or cash flows. Accordingly, with respect to these proceedings, the Company is currently unable to reasonably estimate the possible loss or range of possible loss. Miller Complaint. On November 8, 2018, Ron Miller, a purported stockholder of the Company, filed a Class Action Complaint (the "Miller Complaint") in the United States District Court for the District of Massachusetts (the "Massachusetts District Court") against the Company and three of its former officers (collectively, the "Defendants"), claiming to represent a class of purchasers of Sonus common stock during the period from January 8, 2015 through March 24, 2015 and alleging violations of the federal securities laws. Similar to a previous complaint entitled Sousa et al. vs. Sonus Networks, Inc. et al., which was dismissed with prejudice by an order dated June 6, 2017, the Miller Complaint claims that the Defendants made misleading forward-looking statements concerning Sonus' expected fiscal first quarter of 2015 financial performance, which statements were also the subject of an August 7, 2018 Securities and Exchange Commission Cease and Desist Order, whose findings the Company neither admitted nor denied. The Miller plaintiffs are seeking monetary damages. After the Miller Complaint was filed, several parties filed and briefed motions seeking to be selected by the Massachusetts District Court to serve as a Lead Plaintiff in the action. On June 21, 2019, the Massachusetts District Court appointed a group as Lead Plaintiffs and the Lead Plaintiffs filed an amended complaint on July 19, 2019. On August 30, 2019, the Defendants filed a motion to dismiss the Miller Complaint and, on October 4, 2019, the Lead Plaintiffs filed an opposition to the motion to dismiss. There was an oral argument on the motion to dismiss on February 12, 2020, and on October 20, 2022 the court denied the motion to dismiss. In June 2023, the Defendants agreed to a settlement in principle with the named plaintiffs, and final approval of the settlement was provided by the court on April 24, 2024. The settlement provided a release of all claims asserted in the litigation to all Defendants, who continue to deny liability. The $4.5 million settlement amount was funded by the provider of the Company's Directors and Officers liability insurance policy. Charter Complaint. On September 19, 2022, Charter Communications Operating, LLC (“Charter”) filed two complaints against two of our subsidiaries (Sonus Networks, Inc. and Ribbon Communications Operating Company, Inc.) alleging breach of contract with respect to indemnification obligations purportedly owed to Charter in connection with Charter’s legal dispute with Sprint Communications Company L.P., which was settled by Charter in March 2022. One complaint was filed in the Supreme Court of the State of New York, in New York County; the second complaint was filed by Charter as well as co-plaintiffs Charter Communications Holding Company, LLC and Bright House Networks, LLC, in the Superior Court of the State of Delaware in and for New Castle County. In both complaints, Charter is seeking monetary damages. The Company filed its answer to the first complaint file in New York on December 7, 2022 and to the second complaint filed in Delaware on January 9, 2023. Discovery is on-going and the court in the Delaware complaint has set a preliminary trial date of January 2025. WideOpenWest Complaint. On August 9, 2023, WideOpenWest, Inc. and WideOpenWest Finance, LLC (collectively, “WOW”) filed a complaint against Ribbon alleging breach of contract with respect to indemnification obligations purportedly owed to WOW in connection with WOW’s legal dispute with Sprint Communications Company L.P., which was settled by WOW in the second quarter of 2023. The complaint was filed in the 429th Judicial District of the District Court of the State of Texas, in Collin County, Texas and has since been transferred to the 493rd Judicial District Court in Collin County. In the complaint, WOW is seeking monetary damages. The Company filed its answer to the complaint on October 5, 2023. Discovery is on-going and the court has set a preliminary trial date of December 2024.

v3.24.1.1.u2

SUBSEQUENT EVENT	3 Months Ended
	Mar. 31, 2024
Subsequent Events [Abstract]
SUBSEQUENT EVENT	SUBSEQUENT EVENT On May 15, 2024, the Company entered into a binding commitment letter (the "Commitment Letter") with HPS Investment Partners, LLC ("HPS") and WhiteHorse Capital Management, LLC ("WhiteHorse" and, together with HPS, the "Lenders"), pursuant to which the Lenders have committed to provide the Company with a $385 million senior secured credit facility (the "Refinancing Facility") comprised of (i) a $350 million term loan and (ii) a $35 million revolving credit facility. The funds from the Refinancing Facility will be used to (a) repay 100% of the amounts outstanding under the 2020 Credit Facility (b) redeem in full the Company's outstanding Series A preferred stock and (c) pay fees and expenses related to the Refinancing Facility. Any excess proceeds will be used by the Company for working capital. The funding of the Refinancing Facility is subject to satisfaction of customary closing conditions. The Company expects the Refinancing Facility to close and fund no later than June 30, 2024.

v3.24.1.1.u2

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net loss	$ (30,361)	$ (38,305)

v3.24.1.1.u2

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

v3.24.1.1.u2

BASIS OF PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments, consisting only of normal recurring items, necessary for their fair presentation with accounting principles generally accepted in the United States of America ("GAAP") and with the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). Interim results are not necessarily indicative of results for a full year or any future interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2023, as amended (the "Annual Report"), which was filed with the SEC on February 28, 2024.
Operating Segments	Operating Segments The Company's chief operating decision maker (the "CODM") is its president and chief executive officer. The CODM assesses the Company's performance based on the performance of two separate organizations within Ribbon: the Cloud and Edge segment ("Cloud and Edge") and the IP Optical Networks segment ("IP Optical Networks").
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of Ribbon and its wholly-owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates and Judgments	Use of Estimates and Judgments The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and judgments relied upon in preparing these condensed consolidated financial statements include revenue recognition for multiple element arrangements, inventory valuations, assumptions used to determine the fair value of stock-based compensation and the Preferred Stock and Warrants, intangible asset and goodwill valuations, including impairments, warranty accruals, legal contingencies and recoverability of Ribbon's net deferred tax assets and the related valuation allowances. Ribbon regularly assesses these estimates and records changes in estimates in the period in which they become known. Ribbon bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Transfers of Financial Assets	Transfers of Financial Assets The Company's IP Optical Networks segment maintains customer receivables factoring agreements with a number of financial institutions. Under the terms of these agreements, the Company may transfer receivables to the financial institutions, on a non-recourse basis, provided that the financial institutions approve the receivables in advance. The Company maintains credit insurance policies from major insurance providers or obtains letters of credit from the customers for a majority of its factored trade receivables. The Company accounts for the factoring of its financial assets as a sale of the assets and records the factoring fees, when incurred, as a component of interest expense in the condensed consolidated statements of operations, and the proceeds from the sales of receivables are included in cash from operating activities in the condensed consolidated statements of cash flows.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (the "FASB") issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”), which increases the disclosure requirements around rate reconciliation information and certain types of income taxes companies are required to pay. ASU 2023-09 will be effective for the Company beginning in 2025, with early adoption permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which improves reportable segment disclosure requirements, including enhancement of the disclosures of significant segment expenses and interim disclosure requirements, to enable investors to better understand an entity's overall performance and assess potential future cash flows. ASU 2023-07 will be effective for the Company annually beginning in 2024 and on an interim basis beginning in 2025, with early adoption permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures. In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC's disclosure Update and Simplification Initiative (“ASU 2023-06”), which amends the disclosure or presentation requirements related to various subtopics in the FASB Accounting Standards Codification. This ASU was issued in response to, and to align GAAP with, the SEC's August 2018 final rule that updates and simplifies disclosure requirements. The effective date for the Company for each amendment will be the date on which the SEC's removal of that related disclosure requirement becomes effective, with early adoption prohibited. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements and related disclosures. On February 1, 2023, the FASB staff noted that they believe that the Pillar 2 tax, established by the OECD and intended to apply for tax years beginning in 2024, would be an alternative minimum tax and therefore deferred tax assets would not need to be recognized related to this parallel taxing system. On February 2, 2023, the OECD issued administrative guidance providing transition and safe harbor rules around the implementation of the Pillar 2 global minimum tax. Under an additional transitional safe harbor released July 17, 2023, the undertaxed profits rule top-up tax will not be applied by any constituent entity's jurisdiction of residence with respect to income earned by a company's ultimate parent entity in its jurisdiction of residence, if the ultimate parent entity's jurisdiction has a corporate tax rate of at least 20%. This transition safe harbor will apply to fiscal years beginning on or before December 31, 2025 and ending before December 31, 2026. The Company is closely monitoring developments and evaluating the impacts these new rules will have on its tax rate, including eligibility to qualify for these safe harbor rules. Based upon preliminary calculations for calendar year 2024, the Company anticipates that it will meet the safe harbors in most jurisdictions, and any remaining top-up tax should be immaterial.

v3.24.1.1.u2

BASIS OF PRESENTATION (Tables)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Schedule of Information Regarding Factoring of Accounts Receivable and Associated Fees	Factoring of accounts receivable and associated fees for the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Accounts receivable sold 20,992  21,061  Less factoring fees (391) (455) Net cash proceeds 20,601  20,606

v3.24.1.1.u2

EARNINGS (LOSS) PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Calculations of Shares Used to Compute Loss Per Share	The shares used to compute loss per share were as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Weighted average shares outstanding - basic 172,428  168,541  Potential dilutive common shares —  —  Weighted average shares outstanding - diluted 172,428  168,541

v3.24.1.1.u2

INVENTORY (Tables)	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):   March 31, 2024 December 31, 2023 On-hand final assemblies and finished goods inventories $ 98,290  $ 93,077  Deferred cost of goods sold 1,927  3,269  100,217  96,346  Less noncurrent portion (included in Other assets) (19,459) (18,825) Current portion $ 80,758  $ 77,521

v3.24.1.1.u2

INTANGIBLE ASSETS AND GOODWILL (Tables)	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The Company's intangible assets at March 31, 2024 and December 31, 2023 consisted of the following (in thousands): March 31, 2024 Weighted average amortization period (years) Cost Accumulated amortization Net carrying value Developed technology 7.84 $ 340,380  $ 245,163  $ 95,217  Customer relationships 11.86 268,140  141,423  126,717  Trade names 3.88 5,000  4,927  73  Software licenses 3.00 5,486  2,613  2,873  9.50 $ 619,006  $ 394,126  $ 224,880  December 31, 2023 Weighted average amortization period (years) Cost Accumulated amortization Net carrying value Developed technology 7.84 $ 340,380  $ 239,066  $ 101,314  Customer relationships 11.86 268,140  134,743  133,397  Trade names 3.88 5,000  4,901  99  Software licenses 3.00 5,436  2,159  3,277  9.51 $ 618,956  $ 380,869  $ 238,087
Schedule of Estimated Future Amortization Expense for Intangible Assets	Estimated future amortization expense for the Company's intangible assets at March 31, 2024 was as follows (in thousands): Years ending December 31, Remainder of 2024 $ 37,557  2025 44,105  2026 39,056  2027 33,939  2028 23,400  2029 18,379  Thereafter 28,444  $ 224,880
Schedule of Goodwill	There were no changes to the carrying value of the Company's goodwill in the three months ended March 31, 2024 and 2023. The components of goodwill at both March 31, 2024 and 2023 were as follows (in thousands): Cloud and Edge IP Optical Networks Total   Goodwill $ 392,302  $ 191,996  $ 584,298    Accumulated impairment losses (167,406) (116,000) (283,406) $ 224,896  $ 75,996  $ 300,892

v3.24.1.1.u2

ACCRUED EXPENSES AND OTHER (Tables)	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses at March 31, 2024 and December 31, 2023 consisted of the following (in thousands):   March 31, 2024 December 31, 2023 Employee compensation and related costs $ 29,505  $ 33,682  Professional fees 19,148  19,702  Taxes payable 3,653  8,383  Other 32,185  29,920  $ 84,491  $ 91,687

v3.24.1.1.u2

WARRANTY ACCRUALS (Tables)	3 Months Ended
	Mar. 31, 2024
Guarantees and Product Warranties [Abstract]
Schedule of Changes in Accrual Balance	The changes in the Company's accrual balance in the three months ended March 31, 2024 were as follows (in thousands): Balance at January 1, 2024 $ 12,243  Current period provisions 1,347  Settlements (1,334) Balance at March 31, 2024 $ 12,256

v3.24.1.1.u2

RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES (Tables)	3 Months Ended
	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Accrual Activity	Restructuring and related expense for the three months ended March 31, 2024 and 2023 was comprised of the following (in thousands): Three months ended March 31, 2024 March 31, 2023 Severance and related costs $ 1,616  $ 5,708  Variable and other facilities-related costs 1,449  $ 1,006  Accelerated amortization of lease assets due to cease-use —  $ 223  $ 3,065  $ 6,937  A summary of the 2023 Restructuring Plan accrual activity for the three months ended March 31, 2024 is as follows (in thousands): Balance at January 1, 2024 Initiatives charged to expense Cash payments Net transfer to operating lease accounts Balance at March 31, 2024 Severance $ 671  $ 1,616  $ (1,284) $ —  $ 1,003  A summary of the 2022 Restructuring Plan accrual activity for the three months ended March 31, 2024 is as follows (in thousands): Balance at January 1, 2024 Initiatives charged to expense Cash payments Balance at March 31, 2024 Variable and other facilities-related costs $ 468  1,449  (1,495) $ 422

v3.24.1.1.u2

DEBT (Tables)	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Long Term Debt	The Company had the following outstanding borrowings, unamortized debt issuance costs, letters of credit, interest rates, and remaining borrowing capacity under the 2020 Credit Facility as of March 31, 2024 and December 31, 2023:   March 31, 2024 December 31, 2023 Current portion of Term Debt $ 228,168 $ 35,102 Long-term Debt, net of Current: Long-term Debt, net of Current (Face Amount) $ — $ 200,293 Unamortized Debt Issuance Costs - Contra-Liability — (2,811) Long-term Debt, net of Current $ — $ 197,482 Total Face Amount of Borrowings $ 230,381 $ 235,395 Unamortized Debt Issuance Costs: Other Assets $ 439 $ 557 Current Portion of Term Debt - Contra Liability 2,213 — Long-Term Debt - Contra Liability — 2,811 Total Unamortized Debt Issuance Costs $ 2,652 $ 3,368 Letters of Credit Outstanding $ 2,711 $ 2,711 Remaining Borrowing Capacity $ 72,289 $ 72,289 Average Interest Rates: Term Loan 9.9  % 10.0  % Letters of Credit 4.5  % 4.5  %
Schedule of Debt Maturities	The Company's debt maturities as of March 31, 2024 were as follows: Years ending December 31, Remainder of 2024 $ 30,087  2025 200,294  $ 230,381

v3.24.1.1.u2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	3 Months Ended
	Mar. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Impact of Derivative Financial Instrument on Condensed Consolidated Statement of Operations	The impact of the Company’s derivative financial instrument on its condensed consolidated statements of comprehensive (loss) income for the three months ended March 31, 2024 and 2023 was as follows, net of tax (in thousands): Three months ended   March 31, 2024 March 31, 2023 Gain (loss) recognized in other comprehensive income (loss) on swap, net of tax $ —  $ (2,715) Amount reclassified from accumulated other comprehensive income to other expense, net upon sale of swap, net of tax —  (5,099) Amount reclassified from accumulated other comprehensive income to interest expense (1,321) (3,185) Unrealized gain (loss) on interest rate swap, net of reclassifications and amortization $ (1,321) $ (10,999)

v3.24.1.1.u2

PREFERRED STOCK AND WARRANTS (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule Of Fair Value Of Preferred Stock And Warrants	The Company determined the fair value of the Preferred Stock and Warrants using Level 3 input. The key assumptions into the models utilized were as follows as of March 31, 2024: Preferred Stock (BDT) Face value per share $1,000 Interest payments per year 4 Dividend rate - year 1 (paid in-kind) 9.25% Dividend rate - year 2 (paid in-kind or in cash at the Company's choice) 9.75% Dividend rate - thereafter (paid in cash) 12.00% Yield volatility 25.0% Time to maturity (in years) 1.5 Warrants (Black-Scholes) Stock price $3.20 Strike price $3.77 Risk-free rate 4.35% Volatility 59.2% Dividend yield 0.0% Time to expiration (years) 3.0 The changes in the Company's Preferred Stock and Warrant liabilities the three months ended March 31, 2024 were as follows (in thousands): Preferred stock liability Balance at January 1, 2024 $ 53,337  Payable in-kind dividends 1,355  Fair value change 1,512  Balance at March 31, 2024 $ 56,204  Warrant liability Balance at January 1, 2024 $ 5,295  Fair value change 632  Balance at March 31, 2024 $ 5,927

v3.24.1.1.u2

REVENUE RECOGNITION (Tables)	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Timing of Performance Obligation	The Company's typical performance obligations include the following: Performance Obligation When Performance Obligation is Typically Satisfied When Payment is Typically Due Software and Product Revenue Software licenses (perpetual or term) Upon transfer of control; typically, when made available for download (point in time) Generally, within 30 days of invoicing except for term licenses, which may be paid for over time Software licenses (subscription) Upon activation of hosted site (over time) Generally, within 30 days of invoicing Hardware When control of the hardware passes to the customer; typically, upon delivery (point in time) Generally, within 30 days of invoicing Software upgrades Upon transfer of control; typically, when made available for download (point in time) Generally, within 30 days of invoicing Customer Support Revenue Customer support Ratably over the course of the support contract (over time) Generally, within 30 days of invoicing Professional Services Other professional services (excluding training services) As work is performed (over time) Generally, within 30 days of invoicing (upon completion of services) Training When the class is taught (point in time) Generally, within 30 days of services being performed
Schedule of Disaggregation of Revenue	The Company's revenue for the three months ended March 31, 2024 and 2023 was disaggregated as follows: Three months ended March 31, 2024 Product revenue Service revenue (maintenance) Service revenue (professional services) Total revenue United States $ 26,607  $ 32,847  $ 11,660  $ 71,114  Europe, Middle East and Africa 41,689  17,696  7,698  67,083  Asia Pacific 16,633  10,241  2,927  29,801  Other 2,681  7,597  1,388  11,666  $ 87,610  $ 68,381  $ 23,673  $ 179,664  Three months ended March 31, 2023 Product revenue Service revenue (maintenance) Service revenue (professional services) Total revenue United States $ 38,067  $ 33,073  $ 10,853  $ 81,993  Europe, Middle East and Africa 27,435  20,127  6,575  54,137  Asia Pacific 25,615  9,372  3,144  38,131  Other 2,201  8,016  1,681  11,898  $ 93,318  $ 70,588  $ 22,253  $ 186,159  The Company's product revenue from indirect sales through its channel partner program and from its direct sales program for the three months ended March 31, 2024 and 2023 was as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Indirect sales through channel partner program $ 45,675  $ 35,914  Direct sales 41,935  57,404  $ 87,610  $ 93,318  The Company's product revenue from sales to enterprise customers and from sales to service provider customers for the three months ended March 31, 2024 and 2023 was as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Sales to enterprise customers $ 37,870  $ 27,412  Sales to service provider customers 49,740  65,906  $ 87,610  $ 93,318  The Company's product revenue and service revenue components by segment for the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three months ended March 31, 2024 March 31, 2023 Product revenue:   Cloud and Edge $ 31,513  $ 42,839    IP Optical Networks 56,097  50,479      Total product revenue $ 87,610  $ 93,318  Service revenue:   Maintenance:     Cloud and Edge $ 53,196  $ 54,810      IP Optical Networks 15,185  15,778        Total maintenance revenue 68,381  70,588    Professional services:     Cloud and Edge 16,960  16,831      IP Optical Networks 6,713  5,422        Total professional services revenue 23,673  22,253          Total service revenue $ 92,054  $ 92,841
Schedule of Customer Assets and Liabilities	The changes in the Company's accounts receivable, unbilled receivables and deferred revenue balances for the three months ended March 31, 2024 were as follows (in thousands): Accounts receivable Unbilled accounts receivable Deferred revenue (current) Deferred revenue (long-term) Balance at January 1, 2024 $ 186,938  $ 81,483  $ 113,381  $ 19,218  Increase (decrease), net (43,634) (12,289) (2,785) (5,199) Balance at March 31, 2024 $ 143,304  $ 69,194  $ 110,596  $ 14,019

v3.24.1.1.u2

OPERATING SEGMENT INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The tables below provide revenue, adjusted gross profit and depreciation expense by reportable segment for the three months ended March 31, 2024 and 2023 (in thousands): Three months ended March 31, 2024 March 31, 2023 Segment revenue:   Cloud and Edge $ 101,669  $ 114,480    IP Optical Networks 77,995  71,679      Revenue $ 179,664  $ 186,159  Three months ended March 31, 2024 March 31, 2023 Segment adjusted gross profit:   Cloud and Edge $ 67,119  $ 69,975    IP Optical Networks 31,965  19,500      Total segment adjusted gross profit 99,084  89,475  Stock-based compensation expense (578) (684) Amortization of acquired technology (6,551) (7,389)       Gross profit $ 91,955  $ 81,402  Three months ended March 31, 2024 March 31, 2023 Segment depreciation expense:   Cloud and Edge $ 2,333  $ 2,499    IP Optical Networks 1,061  1,011      Depreciation expense $ 3,394  $ 3,510

v3.24.1.1.u2

MAJOR CUSTOMERS (Tables)	3 Months Ended
	Mar. 31, 2024
Risks and Uncertainties [Abstract]
Schedule of Customer Contributing 10% or More of the Revenue	The following customer contributed 10% or more of the Company's revenue in the three months ended March 31, 2024 and 2023:   Three months ended   March 31, 2024 March 31, 2023 Verizon Communications Inc. * 11% * Less than 10% of total revenue.

v3.24.1.1.u2

STOCK-BASED COMPENSATION PLANS (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Activity Related to Unvested Restricted Stock Grants	The activity related to the Company's RSUs for the three months ended March 31, 2024 was as follows: Shares Weighted Average Grant Date Fair Value Unvested balance at January 1, 2024 7,091,368  $ 3.18  Granted 29,366  $ 2.89  Vested (888,189) $ 5.05  Forfeited (200,229) $ 3.26  Unvested balance at March 31, 2024 6,032,316  $ 2.90
Schedule of Activity Related to Performance Stock Awards	The activity related to the Company's PSUs for the three months ended March 31, 2024 was as follows: Shares Weighted Average Grant Date Fair Value Unvested balance at January 1, 2024 6,297,931  $ 2.07  Granted —  $ —  Vested (31,282) $ 6.40  Forfeited (280,304) $ 9.40  Unvested balance at March 31, 2024 5,986,345  $ 1.70
Schedule of Stock-based Compensation Expenses Which Are Included in Condensed Consolidated Statement of Operations	The condensed consolidated statements of operations include stock-based compensation for the three months ended March 31, 2024 and 2023 as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Product cost of revenue $ 106  $ 149  Service cost of revenue 472  535  Research and development 1,068  1,262  Sales and marketing 1,157  2,129  General and administrative 1,719  1,773  $ 4,522  $ 5,848

v3.24.1.1.u2

LEASES (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Schedule of Right-of-use Lease Assets and Lease Liabilities	The Company's right-of-use lease assets and lease liabilities at March 31, 2024 and December 31, 2023 were as follows (in thousands): Classification March 31, 2024 December 31, 2023 Assets:   Operating lease assets Operating lease right-of-use assets $ 37,110  $ 39,783  Liabilities:     Current Operating Operating lease liabilities $ 14,213  $ 15,739      Non-Current Operating Operating lease liabilities, net of current 36,768  38,711        Total Operating lease liabilities $ 50,981  $ 54,450
Schedule of Components of Lease Expense	The components of lease expense for the three months ended March 31, 2024 and 2023 were as follows (in thousands):   Three months ended   March 31, 2024 March 31, 2023 Operating lease cost* $ 4,199  $ 4,760  Short-term lease cost 3,441  3,427  Variable lease costs (costs excluded from minimum fixed lease payments)** 855  802  Sublease income (260) (430)     Net lease cost $ 8,235  $ 8,559  * No accelerated amortization was recorded in the three months ended March 31, 2024. Operating lease costs for the three months ended March 31, 2023 included $0.2 million of accelerated amortization for certain assets partially or fully vacated with no intent or ability to sublease. ** No variable lease costs were accrued in the three months ended March 31, 2024 or 2023 for future estimated variable expenses related to certain assets partially or fully vacated with no intent or ability to sublease. Other information related to the Company's leases as of March 31, 2024 and December 31, 2023 was as follows:   March 31, 2024 December 31, 2023 Weighted average remaining lease term (years):   Operating leases 5.45 5.50 Weighted average discount rate:   Operating leases 7.04  % 6.34  %
Schedule of Future Minimum Fixed Lease Payments Under Noncancelable Operating Leases	Future minimum fixed lease payments under noncancelable leases at March 31, 2024 were as follows (in thousands):   Operating leases Remainder of 2024 $ 13,873  2025 10,799  2026 9,018  2027 7,857  2028 6,452  2029 13,161    Total lease payments 61,160    Less: interest (10,179)     Present value of lease liabilities $ 50,981

v3.24.1.1.u2

BASIS OF PRESENTATION - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) country segment
Line of Credit Facility [Line Items]
Number of countries (over) | country	30
Number of operating segments | segment	2
2020 Credit Facility
Line of Credit Facility [Line Items]
Repayments of principal in first year	$ 10.0
Repayments of principal in year two	$ 200.4

v3.24.1.1.u2

BASIS OF PRESENTATION - Factoring of Accounts Receivable and Associated Fees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounting Policies [Abstract]
Accounts receivable sold	$ 20,992	$ 21,061
Less factoring fees	(391)	(455)
Net cash proceeds	$ 20,601	$ 20,606

v3.24.1.1.u2

EARNINGS (LOSS) PER SHARE - Calculations of Shares Used to Compute Loss Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Reconciliation of weighted average shares outstanding from basic to diluted
Weighted average shares outstanding—basic (in shares)	172,428	168,541
Potential dilutive common shares (in shares)	0	0
Weighted average shares outstanding—diluted (in shares)	172,428	168,541

v3.24.1.1.u2

EARNINGS (LOSS) PER SHARE - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Mar. 28, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock, par value (in dollars per share)		$ 0.0001		$ 0.0001
Preferred Stock | Private Placement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock issued in equity offering (in shares)	55,000
Share price (in dollars per share)	$ 970
Warrant | Series A Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares of common stock entitled from warrants (in shares)	4,900,000
Warrant | Private Placement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share price (in dollars per share)	$ 3.77
Number of shares of common stock entitled from warrants (in shares)	4,858,090
Warrant | Private Placement | Series A Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Proceeds from issuance of common stock	$ 53.4
Warrant | Private Placement | Series A Preferred Stock | Beneficial Owner
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Proceeds from issuance of common stock	$ 10.0
Warrant | Private Placement | Common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock, par value (in dollars per share)	$ 0.0001
Exercise price of warrants (in dollars per share)	$ 3.77
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities not included in computation of diluted loss per share (in shares)		12,100,000	11,900,000
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities not included in computation of diluted loss per share (in shares)		4,900,000
Exercise price of warrants (in dollars per share)		$ 3.77

v3.24.1.1.u2

INVENTORY (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
On-hand final assemblies and finished goods inventories	$ 98,290	$ 93,077
Deferred cost of goods sold	1,927	3,269
Gross inventory	100,217	96,346
Less noncurrent portion (included in Other assets)	(19,459)	(18,825)
Current portion	$ 80,758	$ 77,521

v3.24.1.1.u2

INTANGIBLE ASSETS AND GOODWILL - Schedule of Intangible Assets and Amortization (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Intangible Assets And Goodwill
Weighted average amortization period (years)	9 years 6 months	9 years 6 months 3 days
Cost	$ 619,006	$ 618,956
Accumulated amortization	394,126	380,869
Net carrying value	224,880	$ 238,087
Estimated future amortization expense for intangible assets
Remainder of 2024	37,557
2025	44,105
2026	39,056
2027	33,939
2028	23,400
2029	18,379
Thereafter	28,444
Total	$ 224,880
Developed technology
Intangible Assets And Goodwill
Weighted average amortization period (years)	7 years 10 months 2 days	7 years 10 months 2 days
Cost	$ 340,380	$ 340,380
Accumulated amortization	245,163	239,066
Net carrying value	$ 95,217	$ 101,314
Customer relationships
Intangible Assets And Goodwill
Weighted average amortization period (years)	11 years 10 months 9 days	11 years 10 months 9 days
Cost	$ 268,140	$ 268,140
Accumulated amortization	141,423	134,743
Net carrying value	$ 126,717	$ 133,397
Trade names
Intangible Assets And Goodwill
Weighted average amortization period (years)	3 years 10 months 17 days	3 years 10 months 17 days
Cost	$ 5,000	$ 5,000
Accumulated amortization	4,927	4,901
Net carrying value	$ 73	$ 99
Software licenses
Intangible Assets And Goodwill
Weighted average amortization period (years)	3 years	3 years
Cost	$ 5,486	$ 5,436
Accumulated amortization	2,613	2,159
Net carrying value	$ 2,873	$ 3,277

v3.24.1.1.u2

INTANGIBLE ASSETS AND GOODWILL - Schedule of Components of Goodwill (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Goodwill [Line Items]
Goodwill	$ 584,298		$ 584,298
Accumulated impairment losses	(283,406)		(283,406)
Goodwill	300,892	$ 300,892	300,892
Cloud and Edge
Goodwill [Line Items]
Goodwill	392,302		392,302
Accumulated impairment losses	(167,406)		(167,406)
Goodwill	224,896		224,896
IP Optical Networks
Goodwill [Line Items]
Goodwill	191,996		191,996
Accumulated impairment losses	(116,000)		(116,000)
Goodwill	$ 75,996		$ 75,996

v3.24.1.1.u2

FAIR VALUE HIERARCHY (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Schedule of Investments [Line Items]
Total Face Amount of Borrowings	$ 230,381	$ 235,395
Fair value of debt	231,500	235,100
Cumulative Preferred Stock
Schedule of Investments [Line Items]
Payable in-kind dividends	5,300
Preferred Stock and Warrant Liabilities
Schedule of Investments [Line Items]
Liabilities, fair value	62,100
Preferred Stock
Schedule of Investments [Line Items]
Payable in-kind dividends	1,355
Term Loan Facility | 2020 Credit Facility
Schedule of Investments [Line Items]
Total Face Amount of Borrowings	$ 230,400	$ 235,400

v3.24.1.1.u2

ACCRUED EXPENSES AND OTHER (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Employee compensation and related costs	$ 29,505	$ 33,682
Professional fees	19,148	19,702
Taxes payable	3,653	8,383
Other	32,185	29,920
Total accrued expenses	$ 84,491	$ 91,687

v3.24.1.1.u2

WARRANTY ACCRUALS - Changes in Accrual Balance (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at January 1, 2024	$ 12,243
Current period provisions	1,347
Settlements	(1,334)
Balance at March 31, 2024	$ 12,256

v3.24.1.1.u2

RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Restructuring Cost and Reserve [Line Items]
Restructuring and related	$ 3,065	$ 6,937
Restructuring reserve current	1,400		$ 1,100
Restructuring reserve noncurrent	1,000		$ 1,100
2023 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related	1,600	5,700
2022 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related	1,400	1,200
2022 Restructuring Plan | Variable and other facilities-related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related	$ 1,449	1,000
2022 Restructuring Plan | Accelerated Amortization Of Lease Assets
Restructuring Cost and Reserve [Line Items]
Restructuring and related		$ 200

v3.24.1.1.u2

RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES - Components of Restructuring Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring and Related Activities [Abstract]
Severance and related costs	$ 1,616	$ 5,708
Variable and other facilities-related costs	1,449	1,006
Accelerated amortization of lease assets due to cease-use	0	223
Restructuring and related expense	$ 3,065	$ 6,937

v3.24.1.1.u2

RESTRUCTURING AND FACILITIES CONSOLIDATION INITIATIVES - Restructuring Accrual Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Reserve [Roll Forward]
Initiatives charged to expense	$ 3,065	$ 6,937
2023 Restructuring Initiative
Restructuring Reserve [Roll Forward]
Initiatives charged to expense	1,600	5,700
2022 Restructuring Plan
Restructuring Reserve [Roll Forward]
Initiatives charged to expense	1,400	1,200
Severance | 2023 Restructuring Initiative
Restructuring Reserve [Roll Forward]
Balance at the beginning of the period	671
Initiatives charged to expense	1,616
Cash payments	(1,284)
Net transfer to operating lease accounts	0
Balance at the end of the period	1,003
Variable and other facilities-related costs | 2022 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance at the beginning of the period	468
Initiatives charged to expense	1,449	$ 1,000
Cash payments	(1,495)
Balance at the end of the period	$ 422

v3.24.1.1.u2

DEBT - Credit Facilities (Details)						3 Months Ended
	Mar. 24, 2023 USD ($)	Jun. 30, 2022 USD ($)	Mar. 10, 2022 USD ($)	Mar. 03, 2021 USD ($)	Aug. 18, 2020 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Mar. 03, 2020 USD ($)
Line of Credit Facility [Line Items]
Principal payments on revolving line of credit						$ 15,000,000	$ 0
Letters of credit outstanding						$ 9,700,000		$ 7,900,000
Letters of Credit
Line of Credit Facility [Line Items]
Debt interest rate						4.50%		4.50%
Term Loan Facility, Term B Loan | Minimum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate		0.50%
Term Loan Facility, Term B Loan | Maximum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate		3.50%
2020 Term Loan
Line of Credit Facility [Line Items]
Quarterly principal payment amount				$ 74,600,000
Write off of capitalized debt issuance costs						$ 2,500,000
Repayment of debt per quarter through March 31, 2024		$ 5,000,000
Repayment of debt for three quarters, thereafter		10,000,000
Repayment of debt, final payment	$ 200,400,000
2020 Credit Facility
Line of Credit Facility [Line Items]
Commitments from lender									$ 500,000,000
Principal payments on revolving line of credit		10,000,000	$ 15,000,000
Accordion feature		$ 50,000,000
Percent of aggregate amount applied for repayment		50.00%
2020 Credit Facility | Debt Instrument, Period Four
Line of Credit Facility [Line Items]
Consolidated net leverage ratio		1.10
2020 Credit Facility | Debt Instrument, Period Five
Line of Credit Facility [Line Items]
Consolidated net leverage ratio		1.25
2020 Credit Facility | Debt Instrument, Period Six
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	1.10
2020 Credit Facility | Debt Instrument, Period Seven
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	1.25
2020 Credit Facility | Maximum | Debt Instrument, Period One
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	4.50	4.75
2020 Credit Facility | Maximum | Debt Instrument, Period Two
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	4.25	3.25
2020 Credit Facility | Maximum | Debt Instrument, Period Three
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	4.00	3.00
2020 Credit Facility | Maximum | Debt Instrument, Period Four
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	3.00
2020 Credit Facility | Maximum | Debt Instrument, Period Five
Line of Credit Facility [Line Items]
Consolidated net leverage ratio	4.00	4.50
2020 Credit Facility | Term Loan Facility
Line of Credit Facility [Line Items]
Commitments from lender									400,000,000
2020 Credit Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitments from lender	$ 75,000,000								100,000,000
Repayments of debt	75,000,000
Debt issuance costs, gross	1,700,000
2020 Credit Facility | Letters of Credit
Line of Credit Facility [Line Items]
Commitments from lender	$ 20,000,000								30,000,000
Debt interest rate	4.50%
Letters of credit outstanding						$ 2,700,000		$ 2,700,000
2020 Credit Facility | Letters of Credit | SOFR
Line of Credit Facility [Line Items]
Basis spread on variable rate						4.50%
2020 Credit Facility | Swingline Loan
Line of Credit Facility [Line Items]
Commitments from lender									$ 20,000,000
2020 Credit Facility | Term Loan Facility, Term B Loan
Line of Credit Facility [Line Items]
Commitments from lender					$ 75,000,000
2020 Credit Facility | Term Loan Facility, Term B Loan | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate					7.50%
2020 Credit Facility | Term Loan Facility, Term B Loan | Minimum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.50%
2020 Credit Facility | Term Loan Facility, Term B Loan | Maximum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate		4.50%
2020 Credit Facility | Term Loan Facility, Term B Loan | Maximum | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate					0.50%
2020 Credit Facility | Term Loan Facility, Term B Loan | Maximum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate		0.50%
2020 Credit Facility | Term Loan Facility, Term A Loan
Line of Credit Facility [Line Items]
Commitments from lender					$ 325,000,000
2020 Credit Facility | Term Loan Facility, Term A Loan | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate					0.50%
2020 Credit Facility | Term Loan Facility, Term A Loan | Minimum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate					1.50%
2020 Credit Facility | Term Loan Facility, Term A Loan | Minimum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate					0.50%
2020 Credit Facility | Term Loan Facility, Term A Loan | Maximum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate					3.50%
2020 Credit Facility | Term Loan Facility, Term A Loan | Maximum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate					2.50%

v3.24.1.1.u2

DEBT - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 24, 2023
Line of Credit Facility [Line Items]
Current portion of Term Debt	$ 228,168	$ 35,102
Long-term Debt, net of Current (Face Amount)	0	200,293
Unamortized Debt Issuance Costs - Contra-Liability	0	(2,811)
Long-term Debt, net of Current	0	197,482
Total Face Amount of Borrowings	230,381	235,395
Other Assets	439	557
Current Portion of Term Debt - Contra Liability	2,213	0
Long-Term Debt - Contra Liability	0	2,811
Total Unamortized Debt Issuance Costs	2,652	3,368
2020 Credit Facility
Line of Credit Facility [Line Items]
Remaining Borrowing Capacity	$ 72,289	$ 72,289
Term Loan
Line of Credit Facility [Line Items]
Average Interest Rates	9.90%	10.00%
Letters of Credit
Line of Credit Facility [Line Items]
Outstanding balance	$ 2,711	$ 2,711
Average Interest Rates	4.50%	4.50%
Letters of Credit | 2020 Credit Facility
Line of Credit Facility [Line Items]
Average Interest Rates			4.50%

v3.24.1.1.u2

DEBT - Schedule of Debt Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
Remainder of 2024	$ 30,087
2025	200,294
Total Debt	$ 230,381	$ 235,395

v3.24.1.1.u2

DEBT - Letters of Credit and Other Guarantees (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Letters of credit outstanding	$ 9.7	$ 7.9
Letters of Credit | 2020 Credit Facility
Line of Credit Facility [Line Items]
Letters of credit outstanding	2.7	2.7
Various Uncommitted Facilities
Line of Credit Facility [Line Items]
Letters of credit outstanding	$ 7.0	$ 5.2

v3.24.1.1.u2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Narrative (Details) - USD ($)					1 Months Ended	3 Months Ended
	Mar. 27, 2023	Mar. 24, 2023	Aug. 16, 2022	Jul. 22, 2022	Aug. 16, 2022	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Mar. 31, 2020
Derivative [Line Items]
Debt balance						$ 230,381,000		$ 235,395,000
Interest Rate Swap
Derivative [Line Items]
Derivative instrument sold	$ 170,000,000	$ 170,000,000	$ 30,000,000	$ 30,000,000	$ 60,000,000
Proceeds from sale	9,800,000	9,400,000	1,600,000	1,500,000
Notional amount		170,000,000	$ 340,000,000	$ 370,000,000	340,000,000
Amount reclassified from accumulated other comprehensive income (loss)	7,300,000				$ 3,100,000
Amortization of derivative instrument						200,000	$ 300,000
Proceeds from sale of derivative, gross	9,400,000	9,000,000
Proceeds from derivative interest	400,000	$ 400,000
Interest Rate Swap | Fair Value, Inputs, Level 2
Derivative [Line Items]
Interest rate derivative						0
2020 Credit Facility | Interest Rate Swap
Derivative [Line Items]
Amount reclassified from accumulated other comprehensive income (loss)	$ 12,000,000
Amortization of derivative instrument						1,600,000
Term Loan Facility | 2020 Credit Facility
Derivative [Line Items]
Debt balance						$ 230,400,000		$ 235,400,000
Principal amount									$ 400,000,000
Fixed rate						0.904%

v3.24.1.1.u2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Impact of Derivative Financial Instrument on Condensed Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivative [Line Items]
Gain (loss) recognized in other comprehensive income (loss) on swap, net of tax	$ 0	$ (2,715)
Unrealized gain (loss) on interest rate swap, net of reclassifications and amortization	(1,321)	(10,999)
Other Income
Derivative [Line Items]
Amount reclassified from accumulated other comprehensive income to interest expense	0	(5,099)
Interest Expense
Derivative [Line Items]
Amount reclassified from accumulated other comprehensive income to interest expense	$ (1,321)	$ (3,185)

v3.24.1.1.u2

PREFERRED STOCK AND WARRANTS - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Mar. 28, 2023	Dec. 31, 2023
Series A Preferred Stock
Dividends Payable [Line Items]
Proceeds from issuance of preferred stock	$ 53.4
Offering expenses paid		$ 3.5
Preferred stock, redemption, percentage year one	103.00%
Preferred stock, redemption, percentage year two	102.00%
Series A Preferred Stock | Beneficial Owner
Dividends Payable [Line Items]
Proceeds from issuance of preferred stock	$ 10.0
Series A Preferred Stock | Dividends Payable in Kind Year One
Dividends Payable [Line Items]
Preferred stock, dividend percentage	9.25%
Series A Preferred Stock | Dividends Payable in Kind Year Two
Dividends Payable [Line Items]
Preferred stock, dividend percentage	9.75%
Series A Preferred Stock | Dividends Payable In Cash Thereafter
Dividends Payable [Line Items]
Preferred stock, dividend percentage	12.00%
Preferred Stock | Private Placement
Dividends Payable [Line Items]
Stock issued in equity offering (in shares)	55,000
Share price (in dollars per share)	$ 970
Warrant | Series A Preferred Stock
Dividends Payable [Line Items]
Number of shares of common stock entitled from warrants (in shares)	4,900,000
Warrant | Private Placement
Dividends Payable [Line Items]
Share price (in dollars per share)	$ 3.77
Number of shares of common stock entitled from warrants (in shares)	4,858,090

v3.24.1.1.u2

PREFERRED STOCK AND WARRANTS - Key Inputs (Details) - Fair Value, Inputs, Level 3	Mar. 31, 2024 $ / shares
Black Scholes Pricing Model | Warrant
Dividends Payable [Line Items]
Time to maturity (in years)	3 years
Black Scholes Pricing Model | Yield volatility | Warrant
Dividends Payable [Line Items]
Measurement Input	0.592
Black Scholes Pricing Model | Stock price | Warrant
Dividends Payable [Line Items]
Measurement Input	3.20
Black Scholes Pricing Model | Strike price | Warrant
Dividends Payable [Line Items]
Measurement Input	3.77
Black Scholes Pricing Model | Risk-free rate | Warrant
Dividends Payable [Line Items]
Measurement Input	0.0435
Black Scholes Pricing Model | Dividend yield | Warrant
Dividends Payable [Line Items]
Measurement Input	0.000
Series A Preferred Stock | Black-Derman-Toy
Dividends Payable [Line Items]
Face value per share	$ 1,000
Time to maturity (in years)	1 year 6 months
Series A Preferred Stock | Black-Derman-Toy | Interest payments per year
Dividends Payable [Line Items]
Measurement Input	4
Series A Preferred Stock | Black-Derman-Toy | Dividend rate - year 1 (paid in-kind)
Dividends Payable [Line Items]
Measurement Input	0.0925
Series A Preferred Stock | Black-Derman-Toy | Dividend rate - year 2 (paid in-kind or in cash at the Company's choice)
Dividends Payable [Line Items]
Measurement Input	0.0975
Series A Preferred Stock | Black-Derman-Toy | Dividend rate - thereafter (paid in cash)
Dividends Payable [Line Items]
Measurement Input	0.1200
Series A Preferred Stock | Black-Derman-Toy | Yield volatility
Dividends Payable [Line Items]
Measurement Input	0.250

v3.24.1.1.u2

PREFERRED STOCK AND WARRANTS - Warrant and Preferred Stock Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Preferred stock liability
Change in fair value of preferred stock liability	$ 1,512	$ 0
Warrant liability
Fair value change	632	$ 0
Preferred Stock
Preferred stock liability
Beginning balance	53,337
Payable in-kind dividends	1,355
Change in fair value of preferred stock liability	1,512
Ending balance	56,204
Warrant
Warrant liability
Beginning balance	5,295
Fair value change	632
Ending balance	$ 5,927

v3.24.1.1.u2

REVENUE RECOGNITION - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Revenue agreement term	1 year
Revenue recognized	$ 51.0	$ 48.0
Customer contract expected life (in years)	5 years
Deferred sales commissions capitalized	$ 3.0		$ 3.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-04-01
Disaggregation of Revenue [Line Items]
Revenue to be recognized	$ 7.0
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Disaggregation of Revenue [Line Items]
Revenue to be recognized	$ 4.0
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Disaggregation of Revenue [Line Items]
Revenue to be recognized	$ 3.0
Revenue, remaining performance obligation, period	1 year

v3.24.1.1.u2

REVENUE RECOGNITION - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 179,664	$ 186,159
Cloud and Edge
Disaggregation of Revenue [Line Items]
Total revenue	101,669	114,480
IP Optical Networks
Disaggregation of Revenue [Line Items]
Total revenue	77,995	71,679
United States
Disaggregation of Revenue [Line Items]
Total revenue	71,114	81,993
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenue	67,083	54,137
Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenue	29,801	38,131
Other
Disaggregation of Revenue [Line Items]
Total revenue	11,666	11,898
Product revenue
Disaggregation of Revenue [Line Items]
Total revenue	87,610	93,318
Product revenue | Cloud and Edge
Disaggregation of Revenue [Line Items]
Total revenue	31,513	42,839
Product revenue | IP Optical Networks
Disaggregation of Revenue [Line Items]
Total revenue	56,097	50,479
Product revenue | Sales to enterprise customers
Disaggregation of Revenue [Line Items]
Total revenue	37,870	27,412
Product revenue | Sales to service provider customers
Disaggregation of Revenue [Line Items]
Total revenue	49,740	65,906
Product revenue | Indirect sales through channel partner program
Disaggregation of Revenue [Line Items]
Total revenue	45,675	35,914
Product revenue | Direct sales
Disaggregation of Revenue [Line Items]
Total revenue	41,935	57,404
Product revenue | United States
Disaggregation of Revenue [Line Items]
Total revenue	26,607	38,067
Product revenue | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenue	41,689	27,435
Product revenue | Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenue	16,633	25,615
Product revenue | Other
Disaggregation of Revenue [Line Items]
Total revenue	2,681	2,201
Service
Disaggregation of Revenue [Line Items]
Total revenue	92,054	92,841
Service revenue (maintenance)
Disaggregation of Revenue [Line Items]
Total revenue	68,381	70,588
Service revenue (maintenance) | Cloud and Edge
Disaggregation of Revenue [Line Items]
Total revenue	53,196	54,810
Service revenue (maintenance) | IP Optical Networks
Disaggregation of Revenue [Line Items]
Total revenue	15,185	15,778
Service revenue (maintenance) | United States
Disaggregation of Revenue [Line Items]
Total revenue	32,847	33,073
Service revenue (maintenance) | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenue	17,696	20,127
Service revenue (maintenance) | Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenue	10,241	9,372
Service revenue (maintenance) | Other
Disaggregation of Revenue [Line Items]
Total revenue	7,597	8,016
Service revenue (professional services)
Disaggregation of Revenue [Line Items]
Total revenue	23,673	22,253
Service revenue (professional services) | Cloud and Edge
Disaggregation of Revenue [Line Items]
Total revenue	16,960	16,831
Service revenue (professional services) | IP Optical Networks
Disaggregation of Revenue [Line Items]
Total revenue	6,713	5,422
Service revenue (professional services) | United States
Disaggregation of Revenue [Line Items]
Total revenue	11,660	10,853
Service revenue (professional services) | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenue	7,698	6,575
Service revenue (professional services) | Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenue	2,927	3,144
Service revenue (professional services) | Other
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,388	$ 1,681

v3.24.1.1.u2

REVENUE RECOGNITION - Schedule of Customer Assets & Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Accounts receivable
Beginning balance	$ 186,938
Increase (decrease), net	(43,634)
Ending balance	143,304
Unbilled accounts receivable
Beginning balance	81,483
Increase (decrease), net	(12,289)
Ending balance	69,194
Deferred revenue (current)
Beginning balance	113,381
Increase (decrease), net	(2,785)
Ending balance	110,596
Deferred revenue (long-term)
Beginning balance	19,218
Increase (decrease), net	(5,199)
Ending balance	$ 14,019

v3.24.1.1.u2

OPERATING SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	2
Segment Reporting Information [Line Items]
Total revenue	$ 179,664	$ 186,159
Total segment adjusted gross profit	99,084	89,475
Stock-based compensation expense	(578)	(684)
Amortization of acquired technology	(6,551)	(7,389)
Gross profit	91,955	81,402
Segment depreciation expense:
Depreciation expense	3,394	3,510
Cloud and Edge
Segment Reporting Information [Line Items]
Total revenue	101,669	114,480
Total segment adjusted gross profit	67,119	69,975
Segment depreciation expense:
Depreciation expense	2,333	2,499
IP Optical Networks
Segment Reporting Information [Line Items]
Total revenue	77,995	71,679
Total segment adjusted gross profit	31,965	19,500
Segment depreciation expense:
Depreciation expense	$ 1,061	$ 1,011

v3.24.1.1.u2

MAJOR CUSTOMERS (Details)	3 Months Ended
	Mar. 31, 2023
Verizon Communications Inc. | Revenue | Customer
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%

v3.24.1.1.u2

STOCK-BASED COMPENSATION PLANS - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) performance_period	Mar. 31, 2023 USD ($)
Stock-based compensation
Fair value of vested restricted and performance-based stock grants	$ 2,610	$ 5,332
Fair value of the assumed awards attributable to future stock-based compensation expense	$ 13,400
Expected period for unrecognized expense	1 year
Performance Shares, Performance Based
Stock-based compensation
Granted percentage	60.00%
Number of performance periods | performance_period	3
Performance Shares, Market Based
Stock-based compensation
Performance period (in years)	3 years
Granted percentage	40.00%
Number of performance periods | performance_period	1
Percent of performance metrics achieved	200.00%
RSAs and RSUs
Stock-based compensation
Fair value of vested restricted and performance-based stock grants	$ 4,500
PSUs
Stock-based compensation
Fair value of vested restricted and performance-based stock grants	$ 200
Minimum | RSAs, RSUs and PSUs
Stock-based compensation
Performance period (in years)	1 year
Maximum | RSAs, RSUs and PSUs
Stock-based compensation
Performance period (in years)	3 years

v3.24.1.1.u2

STOCK-BASED COMPENSATION PLANS - Restricted Stock Awards and Units and Performance-Based Stock Units (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
RSUs
Shares
Unvested balance at the beginning of the period (in shares) | shares	7,091,368
Granted (in shares) | shares	29,366
Vested (in shares) | shares	(888,189)
Forfeited (in shares) | shares	(200,229)
Unvested balance at the end of the period (in shares) | shares	6,032,316
Weighted Average Grant Date Fair Value
Unvested balance at the end of the period (in dollars per share) | $ / shares	$ 3.18
Granted (in dollars per share) | $ / shares	2.89
Vested (in dollars per share) | $ / shares	5.05
Forfeited (in dollars per share) | $ / shares	3.26
Unvested balance at end of the period (in dollars per share) | $ / shares	$ 2.90
PSUs
Shares
Unvested balance at the beginning of the period (in shares) | shares	6,297,931
Granted (in shares) | shares	0
Vested (in shares) | shares	(31,282)
Forfeited (in shares) | shares	(280,304)
Unvested balance at the end of the period (in shares) | shares	5,986,345
Weighted Average Grant Date Fair Value
Unvested balance at the end of the period (in dollars per share) | $ / shares	$ 2.07
Granted (in dollars per share) | $ / shares	0
Vested (in dollars per share) | $ / shares	6.40
Forfeited (in dollars per share) | $ / shares	9.40
Unvested balance at end of the period (in dollars per share) | $ / shares	$ 1.70

v3.24.1.1.u2

STOCK-BASED COMPENSATION PLANS - Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock-based compensation
Stock-based compensation	$ 4,522	$ 5,848
Product cost of revenue
Stock-based compensation
Stock-based compensation	106	149
Service cost of revenue
Stock-based compensation
Stock-based compensation	472	535
Research and development
Stock-based compensation
Stock-based compensation	1,068	1,262
Sales and marketing
Stock-based compensation
Stock-based compensation	1,157	2,129
General and administrative
Stock-based compensation
Stock-based compensation	$ 1,719	$ 1,773

v3.24.1.1.u2

LEASES - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Additional amortization expense	$ 0	$ 223,000
Variable lease cost accrued	0	0
Operating lease, payments	4,800,000	4,800,000
Facility Closing
Lessee, Lease, Description [Line Items]
Accrual for future anticipated variable lease costs	1,400,000		$ 1,500,000
Facility Closing | 2022 Restructuring Plan
Lessee, Lease, Description [Line Items]
Additional amortization expense	$ 0	$ 200,000

v3.24.1.1.u2

LEASES - Right of Use Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Operating lease assets	$ 37,110	$ 39,783
Liabilities:
Current Operating	14,213	15,739
Non-Current Operating	36,768	38,711
Total Operating lease liabilities	$ 50,981	$ 54,450

v3.24.1.1.u2

LEASES - Components of Lease Expense (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases [Abstract]
Operating lease, cost	$ 4,199,000	$ 4,760,000
Short-term lease cost	3,441,000	3,427,000
Variable lease costs (costs excluded from minimum fixed lease payments)	855,000	802,000
Sublease income	(260,000)	(430,000)
Net lease cost	8,235,000	$ 8,559,000
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other (expense) income, net
Accelerated amortization	0	$ 200,000
Variable lease cost accrued	$ 0	$ 0

v3.24.1.1.u2

LEASES - Other Information (Details)	Mar. 31, 2024	Dec. 31, 2023
Weighted average remaining lease term (years):
Operating leases	5 years 5 months 12 days	5 years 6 months
Weighted average discount rate:
Operating leases	7.04%	6.34%

v3.24.1.1.u2

LEASES - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Operating leases
Remainder of 2024	$ 13,873
2025	10,799
2026	9,018
2027	7,857
2028	6,452
2029	13,161
Total lease payments	61,160
Less: interest	(10,179)
Present value of lease liabilities	$ 50,981	$ 54,450

v3.24.1.1.u2

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income tax provisions	$ (3,375)	$ (1,466)

v3.24.1.1.u2

RELATED PARTIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Related Party Transaction [Line Items]
Total revenue	$ 179,664	$ 186,159
Related Party
Related Party Transaction [Line Items]
Total revenue	$ 1,500	$ 800

v3.24.1.1.u2

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions		3 Months Ended
	Sep. 19, 2022 complaint subsidiary	Mar. 31, 2024 USD ($)	Oct. 18, 2023 USD ($)	Nov. 08, 2018 executive	Dec. 31, 2017
Loss Contingencies [Line Items]
Sale of stock grant interest (as a percent)					100.00%
Maximum future royalty commitment		$ 1.8
Maximum future royalty commitment		20.6
Maximum future royalty commitment, interest		$ 1.1
Litigation liability amount			$ 4.5
Miller Complaint
Loss Contingencies [Line Items]
Number of former officers | executive				3
Charter Complaints
Loss Contingencies [Line Items]
Loss contingency, claims filed, number | complaint	2
Loss contingency, number of defendants | subsidiary	2
Minimum
Loss Contingencies [Line Items]
Royalties rates					1.30%
Minimum | LIBOR
Loss Contingencies [Line Items]
Basis spread on variable rate		1.50%
Maximum
Loss Contingencies [Line Items]
Royalties rates					5.00%
Maximum | LIBOR
Loss Contingencies [Line Items]
Basis spread on variable rate		2.75%

v3.24.1.1.u2

SUBSEQUENT EVENT (Details) - USD ($)	May 14, 2024	Mar. 24, 2023	Mar. 03, 2020
2020 Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity			$ 500,000,000
2020 Credit Facility | Term Loan Facility
Subsequent Event [Line Items]
Maximum borrowing capacity			400,000,000
2020 Credit Facility | Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 75,000,000	$ 100,000,000
Subsequent Event | 2024 Credit Agreement
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 385,000,000
Subsequent Event | 2024 Credit Agreement | Term Loan Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	350,000,000
Subsequent Event | 2024 Credit Agreement | Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 35,000,000
Subsequent Event | 2020 Credit Facility
Subsequent Event [Line Items]
Percentage of debt repaid or redeemed	100.00%

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