DZS (DZSI) 10-Q 9 May 23 2023 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2023	May 01, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	000-32743
Entity Registrant Name	DZS INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-3509099
Entity Address, Address Line1	5700 Tennyson Parkway, Suite 400
Entity Address, City or Town	Plano
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75024
City Area Code	469
Local Phone Number	327-1531
Title of 12(b) Security	Common stock, $0.001 par value
Trading Symbol	DZSI
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		31,159,778
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Entity Central Index Key	0001101680
Amendment Flag	false
Document Fiscal Period Focus	Q1

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 28,892	$ 34,347
Restricted cash	1,975	3,969
Accounts receivable - trade, net of allowance for doubtful accounts of $16,087 as of March 31, 2023 and $16,184 as of December 31, 2022	141,029	153,780
Other receivables	21,518	16,144
Inventories	69,722	78,513
Contract assets	605	576
Prepaid expenses and other current assets	10,689	8,371
Total current assets	274,430	295,700
Property, plant and equipment, net	7,135	9,478
Right-of-use assets from operating leases	11,971	12,606
Goodwill	19,952	19,952
Intangible assets, net	30,422	31,742
Other assets	17,013	15,536
Total assets	360,923	385,014
Current liabilities:
Accounts payable - trade	107,904	121,225
Short-term debt – bank, trade facilities and secured borrowings	16,746	9,706
Current portion of long-term debt	23,660	24,073
Contract liabilities	19,476	21,777
Operating lease liabilities	4,859	4,834
Accrued and other liabilities	29,615	27,559
Total current liabilities	202,260	209,174
Long-term debt	0	0
Contract liabilities - non-current	6,636	7,864
Operating lease liabilities - non-current	10,499	11,417
Pension liabilities	11,060	11,021
Other long-term liabilities	2,583	2,806
Total liabilities	233,038	242,282
Commitments and contingencies (Note 13)
Stockholders’ equity:
Common stock, 36,000 shares authorized, 31,102 and 30,968 shares issued and outstanding as of March 31, 2023 and December 31, 2022, respectively, at $0.001 par value	31	30
Additional paid-in capital	276,282	271,884
Accumulated other comprehensive loss	(6,462)	(4,351)
Accumulated deficit	(141,966)	(124,831)
Total stockholders’ equity	127,885	142,732
Total liabilities and stockholders’ equity	$ 360,923	$ 385,014

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 16,087	$ 16,184
Common stock, authorized (in shares)	36,000	36,000
Common stock, issued (in shares)	31,102	30,968
Common stock, outstanding (in shares)	31,102	30,968
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Net revenue		$ 90,812	$ 77,040
Cost of revenue		60,985	50,215
Gross profit		29,827	26,825
Operating expenses:
Research and product development		14,851	11,844
Selling, marketing, general and administrative		24,781	17,742
Restructuring and other charges		4,152	436
Amortization of intangible assets		1,271	294
Total operating expenses		45,055	30,316
Operating loss		(15,228)	(3,491)
Interest expense, net		(792)	(90)
Other income (expense), net		728	(800)
Loss before income taxes		(15,292)	(4,381)
Income tax provision (benefit)		1,843	(1,333)
Net loss		(17,135)	(3,048)
Foreign currency translation adjustments	[1]	(2,051)	(268)
Actuarial loss		(60)	0
Comprehensive loss		$ (19,246)	$ (3,316)
Net loss per share
Basic (in dollars per share)		$ (0.55)	$ (0.11)
Diluted (in dollars per share)		$ (0.55)	$ (0.11)
Weighted average shares outstanding
Basic (in shares)		31,045	27,530
Diluted (in shares)		31,045	27,530
[1]Includes net gain of $0.2 million and net loss of $0.4 million on intra-entity foreign currency transactions that are of a long-term investment nature for three months ended March 31, 2023 and 2022.

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Net gain (loss) on intra-entity foreign currency transactions	$ 0.2	$ (0.4)

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative effect of ASC 326 adoption	Common stock	Additional paid-in capital	Accumulated other comprehensive loss	Accumulated deficit	Accumulated deficit Cumulative effect of ASC 326 adoption
Beginning Balance, Stockholders' equity (in shares) at Dec. 31, 2021			27,505
Beginning Balance, Stockholders' equity at Dec. 31, 2021	$ 131,907	$ (401)	$ 27	$ 223,336	$ (4,457)	$ (86,999)	$ (401)
Issuance of common stock upon vesting of restricted stock units, exercise of stock options and employee stock plan purchases, net of shares withheld for taxes (in shares)			98
Issuance of common stock upon vesting of restricted stock units, exercise of stock options and employee stock plan purchases, net of shares withheld for taxes	156			156
Stock-based compensation	2,671			2,671
Net income (loss)	(3,048)					(3,048)
Subsidiary dissolution	(68)				(68)
Other comprehensive loss	(268)				(268)
Ending Balance, Stockholders' equity (in shares) at Mar. 31, 2022			27,603
Ending Balance, Stockholders' equity at Mar. 31, 2022	$ 130,949		$ 27	226,163	(4,793)	(90,448)
Beginning Balance, Stockholders' equity (in shares) at Dec. 31, 2022	30,968		30,968
Beginning Balance, Stockholders' equity at Dec. 31, 2022	$ 142,732		$ 30	271,884	(4,351)	(124,831)
Issuance of common stock upon vesting of restricted stock units, exercise of stock options and employee stock plan purchases, net of shares withheld for taxes (in shares)			134
Issuance of common stock upon vesting of restricted stock units, exercise of stock options and employee stock plan purchases, net of shares withheld for taxes	(87)		$ 1	(88)
Stock-based compensation	4,486			4,486
Net income (loss)	(17,135)					(17,135)
Other comprehensive loss	$ (2,111)				(2,111)
Ending Balance, Stockholders' equity (in shares) at Mar. 31, 2023	31,102		31,102
Ending Balance, Stockholders' equity at Mar. 31, 2023	$ 127,885		$ 31	$ 276,282	$ (6,462)	$ (141,966)
Accounting Standards Update [Extensible Enumeration]	Cumulative effect of ASC 326 adoption

Unaudited Condensed Consolida_6

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (17,135)	$ (3,048)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	2,465	1,081
Amortization of deferred financing costs	60	0
Stock-based compensation	4,486	2,671
Provision for inventory write-down	1,086	705
Bad debt expense, net of recoveries	(184)	(752)
Provision for sales returns	541	1,448
Provision for warranty	70	121
Unrealized loss (gain) on foreign currency transactions	1,396	874
Subsidiary dissolution	0	(68)
Loss on disposal of property, plant and equipment	40	0
Changes in operating assets and liabilities:
Accounts receivable	11,033	2,761
Other receivable	(5,511)	126
Inventories	7,051	(10,931)
Contract assets	(29)	1,261
Prepaid expenses and other assets	(3,138)	(7,577)
Accounts payable	(13,875)	1,586
Contract liabilities	(3,493)	(1,446)
Accrued and other liabilities	131	456
Net cash used in operating activities	(15,006)	(10,732)
Cash flows from investing activities:
Proceeds from disposal of property, plant and equipment and other assets	1,790	0
Purchases of property, plant and equipment	(775)	(1,317)
Net cash provided by (used in) investing activities	1,015	(1,317)
Cash flows from financing activities:
Repayments of long-term borrowings	(313)	0
Proceeds from short-term borrowings and line of credit, net	8,918	0
Proceeds from related party term loan	4,059	0
Repayments of related party term loan	(5,845)	0
Payments for debt issue costs	(122)	(178)
Proceeds from exercise of stock awards and employee stock plan purchases	(87)	156
Net cash provided by (used in) financing activities	6,610	(22)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(67)	(903)
Net change in cash, cash equivalents and restricted cash	(7,448)	(12,974)
Cash, cash equivalents and restricted cash at beginning of period	38,464	53,639
Cash, cash equivalents and restricted cash at end of period	31,016	40,665
Reconciliation of cash, cash equivalents and restricted cash to statement of financial position
Cash and cash equivalents	28,892	34,160
Restricted cash	1,975	6,343
Long-term restricted cash	149	162
Cash, cash equivalents and restricted cash	31,016	40,665
Cash paid during the period for:
Interest - bank and trade facilities	660	36
Interest - related party	64	0
Income taxes	$ 480	$ 283

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	(1) Organization and Summary of Significant Accounting Policies (a) Description of Business DZS Inc. (referred to, collectively with its subsidiaries, as “DZS” or the “Company”) is global provider of access and optical networking infrastructure and cloud software solutions that enable the emerging hyper-connected, hyper-broadband world and broadband experiences. The Company provides a wide array of reliable, cost-effective networking technologies and software to a diverse customer base. DZS was incorporated under the laws of the state of Delaware in June 1999. The Company is headquartered in Plano, Texas with contract manufacturers and original design manufacturers located in the U.S, India, Korea, China, Taiwan, and Vietnam. The Company also maintains offices to provide sales and customer support at global locations. Through 2022, we also utilized our in-house manufacturing facility in Seminole, Florida. In October 2022, we announced an agreement with Fabrinet, a third-party provider of electro-mechanical and electronic manufacturing and distribution services, to transition the sourcing, procurement, order-fulfillment, manufacturing and return merchandise authorization activities in the Company's Seminole facility to Fabrinet. The transition began in October 2022 and substantially completed in the beginning of 2023, whereupon the Company no longer manufactures its products. (b) Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. GAAP for interim financial information and with the instructions to Form 10-Q and Article 3 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These financial statements include the accounts of the Company and its wholly owned subsidiaries. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission (“SEC”) on March 10, 2023. For a complete description of what the Company believes to be the critical accounting policies and estimates used in the preparation of its unaudited condensed consolidated financial statements, refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. All intercompany transactions and balances have been eliminated in consolidation. Certain prior-year amounts have been reclassified to conform to the current-quarter presentation. The unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) that, in the opinion of management, are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the current interim period are not necessarily indicative of results to be expected for the current year or any other period. (c) Risks and Uncertainties The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. GAAP, assuming the Company will continue as a going concern. We continue to be exposed to macroeconomic pressures in the post-COVID-19 environment, including concerns about energy costs, geopolitical issues, inflation, the availability and cost of credit, business and consumer confidence, and unemployment. We have seen improvement in our supply chain in 2023 as supply chain pricing, freight and logistics costs, product and component availability, and extended lead-times which were a challenge in 2021 and 2022 begin to alleviate in 2023 as the world economy recovers from the COVID-19 pandemic. We expect elevated costs for components and expedite fees to further improve throughout 2023. We conduct significant business in South Korea, Japan, Vietnam, India, Spain, and Canada, as well as in other countries in Europe, Asia-Pacific, Middle East and Latin America, all of which subject us to foreign currency exchange rate risk. The local currencies of our significant foreign subsidiaries are the South Korean Won ("KRW"), Japanese Yen ("JPY"), Euro ("EUR), and Pound Sterling ("GBP"). Revenues and operating expenses are typically denominated in the local currency of each country and result from transactions by our operations in these countries. However, a significant portion of our international cost of sales is denominated in the U.S. Dollar (“USD”). During 2022, the USD appreciated significantly against the KRW, JPY, EUR and GBP which reduced the translated revenues, cost of sales and operating expenses transacted in local currencies, but not the USD based cost of sales, resulting in compressed margins and lower profitability. Late in 2022, exchange rates for these currencies abated somewhat, but the exchange rates for the KRW and JPY remain elevated compared to historical rates. As of March 31, 2023, the Company's debt obligation under the Term Loan was $23.7 million, net of unamortized issuance cost of $0.4 million, of which $1.3 million is scheduled for payment in the next 12 months. Due to the ongoing risk of non-compliance in the next 12 months we continue to classify the entire amount as a current liability. We are currently in discussion with the lenders to amend the debt agreement to mitigate the risk of non-compliance. In addition to negotiating for revised financial covenants, we continue to focus on cost management, operating efficiency and efficient discretionary spending. Management is actively taking measures to enhance profitability and liquidity, including reducing the Company’s cost structure and cash outflows, including its investment in inventory, and managing receivable balances through aggressive collection efforts and tighter customers payment terms.These plans are not completely within the Company’s control, as some actions are dependent on the Company’s lenders, vendors and customers. However, the Company believes that it will maintain liquidity in the next 12 months to support its operations. (d) Use of Estimates The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. 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 unaudited condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ materially from those estimates. (e) Disaggregation of Revenue The following table presents revenues by product technology (in thousands): Three Months Ended March 31, 2023 2022 Access Networking Infrastructure $ 79,459 $ 72,462 Cloud Software & Services 11,353 4,578 Total $ 90,812 $ 77,040 The following table present revenues by geographical concentration (in thousands): Three Months Ended March 31, 2023 2022 Americas $ 24,855 $ 23,061 Europe, Middle East, Africa 19,182 18,649 Asia 46,775 35,330 Total $ 90,812 $ 77,040 (f) Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents and restricted cash, accounts receivables, and contract assets. Cash, cash equivalents and restricted cash consist of financial deposits and money market accounts that are principally held with various domestic and international financial institutions with high credit standing. The Company’s customers include competitive and incumbent local exchange carriers, competitive access providers, internet service providers, wireless carriers and resellers serving these markets. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. Allowances are maintained for potential doubtful accounts based upon the expected collectability of accounts receivable using historical loss rates adjusted for customer-specific factors and current economic conditions. The Company determines historical loss rates on a rational and systematic basis. The Company performs periodic assessments of its customers’ liquidity and financial condition through analysis of information obtained from credit rating agencies, financial statement review and historical and current collection trends. Activity under the Company’s allowance for doubtful accounts consists of the following (in thousands): Three Months Ended March 31, 2023 2022 Balance at beginning of period $ 16,184 $ 17,735 Charged to expense, net of recoveries (184) (752) Utilization and write off — — Cumulative effect of ASC 326 adoption — 401 Foreign exchange impact 87 (326) Balance at end of period $ 16,087 $ 17,058 For the three months ended March 31, 2023, two customers each accounted for 13% of net revenue. For the three months ended March 31, 2022, two customers accounted for 13% and 12% of net revenue, respectively. As of March 31, 2023 and December 31, 2022, no customers represented more than 10% of net accounts receivable. As of March 31, 2023 and December 31, 2022, net accounts receivables from customers in countries other than the United States represented 86%. In 2017, the Company entered into an agreement with a customer in India to supply product for a state sponsored broadband project. The Company substantially completed its obligations under the agreement in 2018. The Company billed the customer, which is a state government sponsored entity, approximately $59.0 million and collected payments of approximately $41.7 million by December 31, 2020. In late March 2021, the customer’s state government parent experienced difficulty passing a budget impacting the ability of the customer to make remaining agreed-upon payments to us. In light of this development, the Company recorded an allowance that covered the entire balance unpaid by the customer. Subsequent to March 2021, the Company recovered approximately $2.5 million of accounts receivable related to the customer. As of March 31, 2023 the Company has a recorded allowance for doubtful accounts of $13.1 million related to this receivable. The Company will continue to pursue collection of the entire outstanding balance and any amounts collected will be recognized in the period which they are received. In the event the Company’s efforts to collect from this customer prove unsuccessful, DZS may seek payment through other means, including through legal action. (g) Business Combinations The Company allocates the fair value of purchase consideration to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. When determining the fair values of assets acquired and liabilities assumed, management makes significant estimates and assumptions, especially with respect to intangible assets and certain tangible assets such as inventory. Critical estimates in valuing certain tangible and intangible assets include but are not limited to future expected cash flows from the underlying assets and discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. Assets acquired and liabilities assumed are generally measured at their acquisition-date fair values. If the initial accounting for a business combination is incomplete by the end of the reporting period in which the combination occurs, the Company reports provisional amounts for the items for which the accounting is incomplete. Those provisional amounts are adjusted during the measurement period (which cannot exceed one year from the acquisition date), or additional assets or liabilities are recognized, to reflect new information obtained about facts and circumstances that existed as of the acquisition date that, if known, would have affected the amounts recognized as of that date. When the consideration transferred by the Company in a business combination includes a contingent consideration arrangement, the contingent consideration is measured at its acquisition-date fair value and included as part of the total consideration transferred in a business combination. Changes in fair value of the contingent consideration that qualify as measurement period adjustments are made retrospectively, with corresponding adjustments against goodwill. Changes in the fair value of the contingent consideration that do not qualify as measurement period adjustments are made in the current period, with corresponding adjustments recognized in earnings. (h) Restructuring and Other Charges From time to time, the Company takes actions to align its workforce, facilities and operating costs with perceived market opportunities, business strategies and changes in market and business conditions. The Company recognizes a liability for the cost associated with an exit or disposal activity in the period in which the liability is incurred, except for one-time employee termination benefits, which are measured at the communication date and recognized ratably over the required service period, if any. (i) Recent Accounting Pronouncements In October 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which requires the Company to apply ASC 606, Revenue from Contracts with Customers, to recognize and measure contract assets and contract liabilities from contracts with customers acquired in a business combination. Before the update such balances were measured and recognized at fair value on the acquisition date. The ASU is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods. The Company adopted these requirements prospectively, effective on the first day of the second quarter of year 2022. There was no material impact on our consolidated financial statements on the adoption date. In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires the Company to measure and recognize expected credit losses for financial assets held and not accounted for at fair value through net income. In November 2018, April 2019 and May 2019, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, and ASU No. 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief, which provided additional implementation guidance on the previously issued ASU. The Company adopted the updated guidance on January 1, 2022, utilizing the modified retrospective transition method and recorded a cumulative-effect adjustment of $0.4 million to retained earnings.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Business Combinations	(2) Business Combinations ASSIA Acquisition On May 27, 2022, the Company acquired certain assets and liabilities of Adaptive Spectrum and Signal Alignment, Incorporated (“ASSIA”), an industry pioneer of broadband access quality-of-experience and service assurance software solutions (the “ASSIA Acquisition”). The core assets acquired include the CloudCheck® Wi-Fi experience management and Expresse® access network optimization software solutions. These software solutions add powerful data analytics and network intelligence capabilities to DZS Cloud, including cloud-managed WiFi solutions, access network optimization and intelligent automation tools. The CloudCheck® and Expresse® solutions are currently deployed in over 125 million connected homes globally, and many of these connections now represent recurring software revenue opportunities for DZS. The initial purchase consideration was $25.0 million, including a $2.5 million holdback that will be released in 13 months following the transaction close date. In October 2022, the Company agreed to pay an additional $1.35 million of purchase consideration to settle certain unresolved matters related to the ASSIA Acquisition. The acquisition was recorded as a business combination with valuation of the assets acquired and liabilities assumed recorded at their acquisition date fair value determined using level three inputs, defined as unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. We completed the purchase price allocation for ASSIA Acquisition in the first quarter of 2023. The following summarizes the final fair values of the assets acquired and liabilities assumed at the date of the ASSIA Acquisition (in thousands): Allocation of purchase consideration Cash and cash equivalents $ 203 Accounts receivable 2,322 Other assets 407 Right-of-use assets 2,172 Property, plant and equipment 232 Intangible assets 30,200 Accounts payable (75) Contract liabilities (19,550) Operating lease liabilities (2,612) Accrued and other liabilities (756) Goodwill 13,807 Total purchase consideration $ 26,350 The purchase price allocation resulted in the recognition of goodwill of approximately $13.8 million, which included the experienced workforce and the expected synergies from combining operations. The Company expects no goodwill to be deductible for tax purposes. The following table represents the final estimated fair value and useful lives of identifiable intangible assets acquired (estimated fair value in thousands): Estimated Estimated Intangible assets acquired Customer relationships $ 18,600 15 years Customer backlog 5,100 10 years Developed technology 6,200 5 - 7 years Tradenames 300 10 years Total intangible assets $ 30,200 Optelian Acquisition On February 5, 2021, the Company acquired Optelian Access Networks Corporation (“Optelian”), a corporation incorporated under the laws of Canada and registered extra-provincially in the Province of Ontario, pursuant to an acquisition agreement whereby the Company purchased all the outstanding shares of Optelian. Following the closing of the transaction, Optelian became the Company’s wholly owned subsidiary. Optelian was a leading optical networking solution provider. This acquisition introduced the “O-Series” to the DZS portfolio of carrier grade optical networking products with up to 400 gigabits per second (Gig) and above capability, expanding the DZS product portfolio by providing environmentally hardened, high capacity, and flexible solutions at the network edge. The purchase price of $7.5 million included cash paid to the shareholders and option holders of Optelian, cash paid to retire Optelian's outstanding debt on the date of acquisition, and contingent payments to shareholders. The payment to shareholders and option holders included a $0.3 million holdback, which was released during the third quarter of 2022, and $1.9 million contingent consideration based on a certain percentage of future revenue of certain Optelian products through the end of 2023. We completed the purchase price allocation for Optelian acquisition in 2021. The purchase price allocation resulted in the recognition of goodwill of approximately $1.9 million, which primarily related to the expected synergies from combining operations. RIFT Acquisition On March 3, 2021, the Company acquired substantially all of the assets of RIFT, Inc., a network automation solutions company, and all the outstanding shares of RIFT.IO India Private Limited, a wholly owned subsidiary of RIFT, Inc. (collectively “RIFT”). RIFT developed a carrier-grade RIFT.ware software platform that simplifies the deployment of any slice, service, or application on any cloud. This acquisition introduced DZS Xtreme, a solution within the DZS Cloud portfolio, to the overall portfolio of DZS systems and software solutions. The total purchase consideration was $0.5 million, including a $0.2 million holdback that was released in April of 2021 following the fulfillment of certain requirements in the purchase agreement. We completed the purchase price allocation for RIFT acquisition in 2021. The purchase price allocation resulted in the recognition of goodwill of approximately $0.2 million, which primarily related to the expected synergies from combining operations.

Fair Value Measurement

Fair Value Measurement	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurement	(3) Fair Value Measurement The Company utilizes a fair value hierarchy that is intended to increase consistency and comparability in fair value measurements and related disclosures. The fair value hierarchy is based on inputs to valuation techniques that are used to measure fair value that are either observable or unobservable. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity’s pricing based upon their own market assumptions. The fair value hierarchy consists of the following three levels: Level 1 Inputs are quoted prices in active markets for identical assets or liabilities. Level 2 Inputs are quoted prices for similar assets or liabilities in an active market, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable and market-corroborated inputs which are derived principally from or corroborated by observable market data. Level 3 Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable Assets and Liabilities Measured at Fair Value on a Recurring Basis: The carrying values of financial instruments such as cash and cash equivalents, restricted cash, accounts and other receivables, accounts payable and accrued liabilities approximate their fair values based on their short-term nature. The carrying value of the Company's debt approximates its fair values based on the current rates available to the Company for debt of similar terms and maturities. The Company classifies its contingent liability from Optelian acquisition within Level 3 as it includes inputs not observable in the market. The Company estimates the fair value of contingent consideration as the present value of the expected contingent payments, determined using the revenue forecast for certain Optelian products through the end of 2023. The fair value of contingent liability is generally sensitive to changes in the revenue forecast during the payout period. The change in the respective fair value is included in selling, marketing, general and administrative expenses on the unaudited condensed consolidated statement of comprehensive income (loss). The following table reconciles the beginning and ending balances of the Company’s Level 3 contingent liability (in thousands): Three Months Ended March 31, 2023 2022 Balance at beginning of period $ 1,156 $ 2,121 Cash payments — — Net change in fair value 27 51 Balance at end of period $ 1,183 $ 2,172

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	3 Months Ended
	Mar. 31, 2023
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	(4) Cash, Cash Equivalents and Restricted Cash As of March 31, 2023 and December 31, 2022, the Company's cash, cash equivalents and restricted cash consisted of financial deposits. Cash, cash equivalents and restricted cash held within the U.S. totaled $16.8 million and $24.9 million as of March 31, 2023 and December 31, 2022, respectively. Cash, cash equivalents and restricted cash held within the U.S. are held at FDIC insured depository institutions. Cash, cash equivalents and restricted cash held outside the U.S. totaled $14.1 million and $13.6 million as of March 31, 2023 and December 31, 2022, respectively. Restricted cash consisted primarily of cash collateral for performance bonds and warranty bonds. Long-term restricted cash was $0.1 million and $0.2 million as of March 31, 2023 and December 31, 2022, respectively, and is included in other assets on the unaudited condensed consolidated balance sheets.

Balance Sheet Details

Balance Sheet Details	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	(5) Balance Sheet Details Balance sheet detail as of March 31, 2023 and December 31, 2022 is as follows (in thousands): Inventories March 31, 2023 December 31, 2022 Raw materials $ 35,870 $ 37,354 Work in process 699 1,050 Finished goods 33,153 40,109 Total inventories $ 69,722 $ 78,513 Inventories are stated at the lower of cost or net realizable value, with cost being computed based on an adjusted standard basis, which approximates actual cost on an average or first-in, first-out basis. Property, plant and equipment March 31, 2023 December 31, 2022 Property, plant and equipment, net: Machinery and equipment $ 12,971 $ 17,214 Leasehold improvements 2,440 5,683 Computers and software 4,608 4,713 Furniture and fixtures 2,108 1,748 Construction in progress and other 1,358 1,264 23,485 30,622 Less: accumulated depreciation and amortization (16,285) (21,062) Less: government grants (65) (82) Total property, plant and equipment, net $ 7,135 $ 9,478 Depreciation expense associated with property, plant and equipment for the three months ended March 31, 2023 and March 31, 2022 was $1.2 million and $0.8 million, respectively. Warranties The Company accrues warranty costs based on historical trends for the expected material and labor costs to provide warranty services. The Company's standard warranty period is one year from the date of shipment with the ability for customers to purchase an extended warranty of up to five years from the date of shipment. The following table summarizes the activity related to the product warranty liability: Three Months Ended March 31, 2023 2022 Balance at beginning of period $ 1,896 $ 1,981 Charged to cost of revenue 70 121 Claims and settlements (113) (149) Foreign exchange impact 21 (17) Balance at end of period $ 1,874 $ 1,936 Contract Balances The Company records contract assets when it has a right to consideration and records accounts receivable when it has an unconditional right to consideration. Contract liabilities consist of cash payments received (or unconditional rights to receive cash) in advance of fulfilling performance obligations. The majority of the Company's performance obligations in its contracts with customers relate to contracts with duration of less than one year. The opening and closing balances of current and long-term contract assets and contract liabilities related to contracts with customers are as follows: Contract Contract December 31, 2022 $ 576 $ 29,641 March 31, 2023 $ 605 $ 29,225 The decrease in contract liabilities during the three months ended March 31, 2023 was primarily due to the revenue recognition criteria being met for previously deferred revenue, partially offset by invoiced amounts that did not yet meet the revenue recognition criteria. The amount of revenue recognized in the three months ended March 31, 2023 that was included in the prior period contract liability balance was $7.4 million. This revenue consists of services provided to customers who had been invoiced prior to the current year. We expect to recognize approximately 75% of outstanding contract liabilities as revenue over the next 12 months and the remainder thereafter. The balance of contract cost deferred as of March 31, 2023 and December 31, 2022 was $0.5 million and $1.0 million, respectively. During the three months ended March 31, 2023, the Company recorded $0.5 million in amortization related to contract cost deferred as of December 31, 2022.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	(6) Goodwill and Intangible Assets The following table summarizes the activity related to goodwill (in thousands): March 31, 2023 2022 Balance at beginning of period, gross $ 20,955 $ 7,148 Accumulated impairment at beginning of period (1,003) (1,003) Goodwill from acquisitions — — Foreign exchange impact — — Balance at end of period $ 19,952 $ 6,145 Intangible assets consisted of the following (in thousands): March 31, 2023 Gross Carrying Accumulated Net Customer relationships $ 24,331 $ (5,451) $ 18,880 Customer backlog 5,100 (723) 4,377 Developed technology 11,207 (4,822) 6,385 In-process research and development 890 (385) 505 Tradenames 300 (25) 275 Total intangible assets, net $ 41,828 $ (11,406) $ 30,422 December 31, 2022 Gross Carrying Accumulated Net Customer relationships $ 24,330 $ (4,759) $ 19,571 Customer backlog 5,100 (506) 4,594 Developed technology 11,207 (4,463) 6,744 In-process research and development 890 (340) 550 Tradenames 300 (17) 283 Total intangible assets, net $ 41,827 $ (10,085) $ 31,742 Amortization expense associated with intangible assets for the three months ended March 31, 2023 and March 31, 2022 was $1.3 million and $0.3 million, respectively. The following table presents the future amortization expense of the Company’s intangible assets as of March 31, 2023 (in thousands): Remainder of 2023 $ 3,962 2024 5,283 2025 5,278 2026 4,095 2027 3,143 Thereafter 8,661 Total $ 30,422

Debt

Debt	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Debt	(7) Debt The following table summarizes the Company’s debt (in thousands): March 31, 2023 December 31, 2022 JPMorgan Term Loan, long-term $ — $ — JPMorgan Term Loan, current portion 24,063 24,375 Unamortized debt issuance costs (403) (302) Long-term debt, including current portion $ 23,660 $ 24,073 JPMorgan Revolving Credit Facility $ 12,000 $ 4,000 Industrial Bank of Korea Loan 919 — DNI Related Party Loan 3,827 5,706 Short-term debt and credit facilities $ 16,746 $ 9,706 Total Debt $ 40,406 $ 33,779 JPMorgan Credit Agreement On February 9, 2022, the Company entered into a Credit Agreement (the “Credit Agreement”) by and between the Company, as borrower, certain subsidiaries of the Company, as guarantors, the lenders party thereto and JPMorgan Chase Bank, N.A., as administrative agent. The Credit Agreement originally provided for revolving loans (the "Revolving Credit Facility") in an aggregate principal amount of up to $30.0 million, up to $15.0 million of which is available for letters of credit, and was scheduled to mature on February 9, 2024. The maximum amount that the Company can borrow under the Credit Agreement is subject to a borrowing base, which is based on a percentage of eligible accounts receivable and eligible inventory, subject to reserves and other adjustments, plus $10.0 million. On May 27, 2022, the Company entered into a First Amendment to Credit Agreement (the “Amendment”), which amends the Credit Agreement dated February 9, 2022 with the Company, as borrower, certain subsidiaries of the Company, as guarantors, the lenders party thereto and JPMorgan Chase Bank, N.A., as administrative agent. The Amendment, among other things, (1) provides for a term loan (the “Term Loan”) in an aggregate principal amount of $25.0 million with a maturity date of May 27, 2027, (2) extends the maturity date of the $30.0 million Revolving Credit Facility to May 27, 2025, (3) permits the ASSIA Acquisition, (4) modifies the applicable margin for borrowings under the Credit Agreement to be, at the Company’s option, either (i) the adjusted term SOFR rate plus a margin ranging from 3.0% to 3.5% per year or (ii) the prime rate plus a margin ranging from 2.0% to 2.5% per year, in each case depending on the Company’s leverage ratio, (5) modifies the letter of credit fee such that it ranges from 3.0% to 3.5%, depending on the Company’s leverage ratio, (6) modifies the commitment fee on the unused portion of the Revolving Credit Facility to range from 0.25% to 0.35% per year, depending on the Company’s leverage ratio, (7) modifies the method of calculating the leverage ratio, and (8) modifies the financial covenants to (i) increase the maximum permitted leverage ratio to 3.00 to 1.00 through September 30, 2022, 2.50 to 1.00 thereafter through September 30, 2023, and 2.00 to 1.00 thereafter and (ii) replace the minimum liquidity requirement with a minimum permitted fixed charge coverage ratio of 1.25 to 1.00. On May 27, 2022, the Company borrowed the full amount of the Term Loan to finance the ASSIA Acquisition. On February 15, 2023, the Company entered into a Second Amendment to Credit Agreement (the "Second Amendment"), which amends the Credit Agreement dated February 9, 2022 (as previously amended on May 27, 2022). The Second Amendment, among other things, (1) modifies the financial covenants to (i) suspend the maximum leverage ratio requirement of 2.50 to 1.00 until the fiscal quarter ending September 30, 2023 and (ii) suspend the minimum fixed charge coverage ratio requirement of 1.25 to 1.00 until the fiscal quarter ending December 31, 2023, (2) adds new financial covenants to require (i) minimum liquidity of $30.0 million for the fiscal quarter ending March 31, 2023, $35.0 million for the fiscal quarters ending June 30, 2023 and September 30, 2023, and $20.0 million at any time until September 30, 2023, and (ii) minimum EBITDA (as defined in the Credit Facility) of ($1 million) for the fiscal quarter ending March 31, 2023 and $1 for the fiscal quarter ending June 30, 2023, (3) increases the applicable margin for adjusted term SOFR borrowings and prime rate borrowings to 4.0% and 3.0%, respectively, when the Company’s leverage ratio exceeds 2.50 to 1.00, (4) increases the commitment fee on the unused portion of the revolving commitment to 0.40% per year when the Company’s leverage ratio exceeds 2.50 to 1.00, and (5) prohibits dividends and other distributions and tightens certain covenants. On May 8, 2023, the Company entered into a Third Amendment to the Credit Agreement (the "Third Amendment"), which amends the Credit Agreement dated February 9, 2022 (as previously amended on May 27, 2022 and February 15, 2023). The Third Amendment, among other things, (1) modifies the financial covenants to eliminate the minimum EBITDA (as defined in the Credit Facility) of ($1 million) for the fiscal quarter ending March 31, 2023, (2) decreases the calculation of the borrowing base by $5 million through June 30, 2023 and an additional $5 million thereafter, (3) reduces the amount of the Revolving Credit Facility commitment to $25 million effective June 15, 2023, and (4) increases the applicable margin for adjusted term SOFR borrowings and prime rate borrowings to 4.5% and 3.5%, respectively, when the Company’s leverage ratio exceeds 2.50 to 1.00. As of March 31, 2023, the Company's debt obligation under the Term Loan was $23.7 million, net of unamortized issuance cost of $0.4 million, and of which $1.3 million is scheduled for payment in the next 12 months. The Company had $12.0 million outstanding debt and $1.2 million in letters of credit issued under the $30.0 million Revolving Credit Facility as of March 31, 2023, and, after entering into the Third Amendment, $16.8 million was available to the Company for additional borrowing under the Revolving Credit Facility. Due to the ongoing risk of non-compliance with certain financial covenants in the next 12 months, we presented our contractual long-term debt obligation of $22.8 million and $23.1 million as of March 31, 2023 and December 31, 2022, respectively, within the current portion of long-term debt on the unaudited condensed consolidated balance sheets. We are currently in discussion with the lenders to amend the debt agreement to mitigate the risk of non-compliance. While the borrowings under the term loan are currently classified as a current liability, the Company believes that it will maintain liquidity in the next 12 months to support its operations. The future principal maturities of the Term Loan for each of the next five years are as follows (in thousands): Remainder of 2023 $ 938 2024 1,563 2025 1,875 2026 2,188 2027 17,499 Total $ 24,063 Related Party Debt On October 31, 2022, DNS Korea, the Company’s wholly-owned subsidiary, entered into a Loan Agreement with DNI (the “November 2022 DNI Loan”). The November 2022 DNI Loan was negotiated and approved on behalf of the Company and its subsidiaries by the audit committee of the Board of Directors of the Company which consists of directors determined to be independent from DNI. The November 2022 DNI Loan consisted of a term loan in the amount of KRW 7.2 billion ($5.0 million USD), with interest payable monthly at an annual rate of 6.0%. In the first quarter of 2023, the entire outstanding balance on the November 2022 DNI Loan was repaid and DNS Korea entered into a new short-term loan arrangement with DNI (the “February 2023 DNI Loan”) and borrowed KRW 5.0 billion ($4.1 million USD), with interest payable monthly at an annual rate of 7.0%. The Company's debt obligation under the February 2023 DNI Loan was KRW 5.0 billion ($3.8 million USD) as of March 31, 2023. The entire outstanding balance on the February 2023 DNI Loan was repaid in the second quarter of 2023. As security for the February 2023 DNI Loan, DNS Korea granted a security interest to DNI in inventory of KRW 35.0 billion ($26.8 million USD) in its Janghowon warehouse, which should be maintained at a minimum of KRW 10.0 billion ($7.7 million USD), and account receivable for two certain customers in the amount to KRW 16.2 billion ($12.4 million USD). Industrial Bank of Korea Loan

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2023
Retirement Benefits [Abstract]
Employee Benefit Plans	(8) Employee Benefit Plans Defined Contribution Plans The Company maintains a 401(k) plan for its employees in the US whereby eligible employees may contribute up to a specified percentage of their earnings, on a pretax basis, subject to the maximum amount permitted by the Internal Revenue Code. Under the 401(k) plan, the Company made discretionary contributions to the plan in 2022. For the three months ended March 31, 2023, the Company recorded an expense of $0.3 million. For the three months ended March 31, 2022, the Company recorded an expense of $0.2 million. The Company maintains a defined contribution plan for its employees in Korea. Under the defined contribution plan, the Company contributes the equivalent of 8.3% of an employee's gross salary into the plan. For each of the three months ended March 31, 2023 and March 31, 2022 the Company recorded an expense of $0.3 million. Defined Benefit Plans The Company sponsors defined benefit plans for its employees in Germany and Japan. Defined benefit plans provide pension benefits based on compensation and years of service. The Germany plans were frozen as of September 30, 2003 and have not been offered to new employees after that date. The Company has recorded the underfunded status as of March 31, 2023 and December 31, 2022 as a long-term liability on the unaudited condensed consolidated balance sheets. The accumulated benefit obligation for the plans in Germany and Japan was $11.1 million and $11.0 million as of March 31, 2023 and December 31, 2022, respectively. Periodic benefit costs for each of the three months ended March 31, 2023 and March 31, 2022 were $0.1 million. The Company holds pension insurance contracts, with the Company as beneficiary, in the amount of $2.5 million as of March 31, 2023 and December 31, 2022 related to individuals under the pension plans. The Company records these insurance contracts based on their cash surrender value at the balance sheet dates. These insurance contracts are classified as other assets on the Company’s unaudited condensed consolidated balance sheet. The Company intends to use any proceeds from these policies to fund the pension plans. However, since the Company is the beneficiary on these policies, these assets have not been designated pension plan assets.

Restructuring and Other Charges

Restructuring and Other Charges	3 Months Ended
	Mar. 31, 2023
Restructuring and Related Activities [Abstract]
Restructuring and Other Charges	(9) Restructuring and Other Charges In 2021, the Company made the strategic decision to relocate manufacturing functions of DZS GmbH and Optelian to Seminole, Florida and to transition the above subsidiaries to sales and research and development centers. For the three months ended March 31, 2022, the Company recorded $0.4 million of related restructuring costs. The restructuring of DZS GmbH and Optelian was completed in 2022 and no related restructuring costs were recorded for the three months ended March 31, 2023. On September 17, 2022, DZS signed an agreement with Fabrinet, a third-party provider of electro-mechanical and electronic manufacturing and distribution services, to transition the sourcing, procurement, order-fulfillment, manufacturing and return merchandise authorization activities in the Company's Seminole, Florida facility to Fabrinet. The transition to Fabrinet began in October 2022 and substantially completed in the beginning of 2023. Post transition, the DZS Seminole, Florida-based operations, supply chain and manufacturing workforce will be reduced by approximately two-thirds and the remaining team is expected to be relocated to an appropriately sized facility. For the three months ended March 31, 2023, the Company record ed $3.5 million of restructuring related costs, consisting of freight and expedite fees of $1.0 million, facility and labor costs of $0.8 million, accelerated depreciation of manufacturing related assets of $0.4 million, termination-related benefits of $0.3 million, inventory write-off of $0.5 million, and other costs of $0.5 million. The Company accounted for the one-time employee termination benefits in accordance with ASC 420, Exit or Disposal Cost Obligations, and recognized the respective liability when the final terms of the benefit arrangement were communicated to the affected employees. As of March 31, 2023, the Company had $0.6 million liability related to termination benefits associated with Seminole restructuring. For the three months ended March 31, 2023, the Company also included in restructuring and other charges approximately $0.3 million of facility costs related to impaired facilities and $0.4 million of non-capitalizable implementation costs related to replacement of the Company’s legacy enterprise resource planning and reporting software.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
Related Party Transactions	(10) Related Party Transactions Related Party Debt As of March 31, 2023, the Company had KRW 5.0 billion ($3.8 million USD) outstanding of the related party borrowing from DNI. See Note 7 Debt for additional information about the Company’s related party debt. The following table sets forth payment guarantees of the Company's obligations as of March 31, 2023 that have been provided by Dasan Networks, Inc. ("DNI"). DNI owns approximately 29.2% of the outstanding shares of the Company's common stock. The amount guaranteed exceeds the principal amounts of outstanding obligations due to collateral requirements by the banks. Guarantor Amount Guaranteed Description of Obligations Guaranteed Dasan Networks, Inc. $ 4,422 Payment guarantee to Industrial Bank of Korea Dasan Networks, Inc. 3,068 Payment guarantee to Shinhan Bank $ 7,490 Other Related Party Transactions Sales, cost of revenue, operating expense, interest expense and other expenses to and from related parties were as follows (in thousands) for the three months ended March 31, 2023 and 2022: Three Months Ended March 31, 2023 Counterparty Sales Cost of Operating Expense Interest Other Dasan Networks, Inc. $ 153 $ 128 $ 294 $ 79 $ 16 Three Months Ended March 31, 2022 Counterparty Sales Cost of Operating Expense Interest Other Dasan Networks, Inc. $ 198 $ 177 $ 407 $ — $ 17 The Company has entered into sales agreements with DNI to sell certain services and finished goods produced by the Company. The Company also has an agreement with DNI in which DNI acts as a sales channel to third party customers. The above transactions are included in sales and cost of revenue on the unaudited condensed consolidated statement of comprehensive income (loss). Sales to DNI are recorded net of royalty fees for a sales channel arrangement. DNS Korea has a lease agreement with DNI related to the lease of a warehouse facility. Operating lease cost related to the DNI lease totaled $0.1 million for the three months ended March 31, 2023. Operating lease cost related to the DNI leases totaled $0.2 million for the three months ended March 31, 2022. Operating lease expense is allocated between cost of revenue, research and product development, and selling, marketing, general and administrative expenses on the unaudited condensed consolidated statement of comprehensive income (loss). As of March 31, 2023, the right-of-use asset and operating lease liability related to DNI leases were $1.6 million. As of December 31, 2022, the right-of-use asset and operating lease liability related to DNI leases were $1.7 million. The Company also pays a license fee under the Trademark License Agreement with DNI. The license fee is calculated as 0.4% of DNS Korea annual sales. For the three months ended March 31, 2023, license related expense were $0.2 million. For the three months ended March 31, 2022, license related expense were $0.1 million. License related expense are included in selling, marketing, general and administrative expenses on the consolidated statements of comprehensive income (loss). Interest expense represents interest paid to DNI for the related party debt. Interest due to DNI was included in accrued and other liabilities on the unaudited condensed consolidated balance sheets as of March 31, 2022 and December 31, 2022. See Note 7 Debt for additional information about the Company’s related party debt. Other expenses represent charges from DNI for its payment guarantees relating to the Company's obligations. The Company pays DNI a guarantee fee which is calculated as 0.9% per annum of the guaranteed amount. Refer to the table above for further information about obligations guaranteed by DNI. Balances of Receivables and Payables with Related Parties Balances of receivables and payables arising from sales and purchases of goods and services with related parties as of March 31, 2023 and December 31, 2022 were included in the following balance sheet captions on the unaudited condensed consolidated balance sheets, as follows (in thousands): As of March 31, 2023 Counterparty Account Other Loans Payable Accounts Accrued and other liabilities Dasan Networks, Inc. $ 224 $ — $ 3,827 $ 895 $ 212 As of December 31, 2022 Counterparty Account Other Loans Payable Accounts Accrued and other liabilities Dasan Networks, Inc. $ 943 $ 123 $ 5,706 $ 1,019 $ 483

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	(11) Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing the net income (loss) for the period by the weighted average number of shares of common stock outstanding during the period. The calculation of diluted net income (loss) per share gives effect to common stock equivalents; however, potential common stock equivalents are excluded if their effect is antidilutive. Potential common stock equivalents are composed of incremental shares of common stock issuable upon the exercise of stock options and the vesting of restricted stock units. In periods when a net loss is reported, all common stock equivalents are excluded from the calculation because they would have an anti-dilutive effect, meaning the loss per share would be reduced. Therefore, in periods when a loss is reported, basic and dilutive loss per share are the same. The following table is a reconciliation of the numerator and denominator in the basic and diluted net income (loss) per share calculation (in thousands, except per share data) for the three months ended March 31, 2023, and 2022: Three months ended March 31, 2023 2022 Net income (loss) $ (17,135) $ (3,048) Weighted average number of shares outstanding: Basic 31,045 27,530 Effect of dilutive securities: Stock options, restricted stock units and share awards — — Diluted 31,045 27,530 Net income (loss) per share: Basic $ (0.55) $ (0.11) Diluted $ (0.55) $ (0.11) The following table sets forth potential common stock that is not included in the diluted net income (loss) per share calculation above because their effect would be anti-dilutive for the periods indicated (in thousands): Three months ended March 31, 2023 2022 Outstanding stock options 563 939 Unvested restricted stock units 500 278

Leases

Leases	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Leases	(12) Leases The Company leases certain properties and buildings (including manufacturing facilities, warehouses, and office spaces) and equipment under various arrangements which provide the right to use the underlying asset and require lease payments for the lease term. The Company’s lease portfolio consists of operating leases which expire at various dates through 2028. Assets and liabilities related to operating leases are included in the consolidated balance sheets as right-of-use assets from operating leases, operating lease liabilities - current and operating lease liabilities - non-current. The Company recognizes minimum rental expense on a straight-line basis based on the fixed components of a lease arrangement. The Company amortizes this expense over the term of the lease beginning with the date of initial possession, which is the date the lessor makes an underlying asset available for use. For the three months ended March 31, 2023, the Company recognized lease expense of $1.0 million. For the three months ended March 31, 2022, the Company recognized lease expense of $1.2 million. The following table presents the maturity of the Company’s operating lease liabilities as of March 31, 2023 (in thousands): Remainder of 2023 $ 4,209 2024 5,131 2025 3,575 2026 2,232 2027 1,121 Thereafter 693 Total operating lease payments 16,961 Less: imputed interest (1,603) Total operating lease liabilities $ 15,358

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	(13) Commitments and Contingencies Performance Guarantees In the normal course of operations, from time to time, the Company arranges for the issuance of various types of performance guarantees, such as standby letters of credit or surety bonds. These instruments are arrangements under which the financial institution or surety provides a financial guarantee that the Company will perform in accordance with contractual or legal obligations. As of March 31, 2023, the Company had $15.6 million of performance guarantees in the form of bank guarantees or surety bonds guaranteed by third parties. Trade Compliance Matter During the first quarter of 2022, the Company received a notice letter from the Office of the Commissioner of Customs, Chennai II of the India Department of Revenue (the “Notice”) claiming the Company had allegedly mis-declared and incorrectly classified certain products imported to India by the Company at the time of clearance of customs. The Notice claims that due to such mis-declaration and incorrect classification of the imported products, the Company and its contract manufacturer in India underpaid duties approximating INR 299.6 million ($3.6 million USD based on exchange rates as of March 31, 2023) related to such products. The documents relied upon in the Notice were requested by the Company, however they are yet to be received. In the second quarter of 2023, the Company received a second notice letter issued by the Office of the Principal Commissioner of Customs (Air Cargo) Complex, Chennai VII Commissionerate claiming the alleged underpaid duties approximated INR 389.3 million ($4.7 million based on exchange rates as of March 31, 2023). The two notice letters cover substantially the same shipments and overlap in scope. The Company intends to vigorously defend itself in this matter. As we have not yet received the full contents of the Notice, we are unable to estimate a potential loss related to this matter, if any, which could range up to the full amount of the alleged unpaid duties, plus penalties and interest. In addition to the Notice discussed above, from time to time, the Company is subject to various legal proceedings, claims and litigation arising in the ordinary course of business. While the outcome of these matters is currently not determinable, the Company records an accrual for legal contingencies that it has determined to be probable to the extent that the amount of the loss can be reasonably estimated. The Company does not expect that the ultimate costs to resolve these matters will have a material adverse effect on its consolidated financial position, results of operations or cash flows. However, litigation is subject to inherent uncertainties, and unfavorable rulings could occur. If an unfavorable ruling were to occur, there exists the possibility of a material adverse impact on the results of operations and cash flows of the reporting period in which the ruling occurs, or future periods.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	(14) Income Taxes Income tax expense for the three months ended March 31, 2023 was approximately $1.8 million on pre-tax loss of $15.3 million. Income tax benefit for the three months ended March 31, 2022 was approximately $1.3 million on pre-tax loss of $4.4 million. As of March 31, 2023, the income tax rate varied from the United States statutory income tax rate primarily due to valuation allowances in North America, EMEA and Asia, mandatory R&D expense capitalization in the U.S., and foreign and state income tax rate differentials. Consistent with the prior periods, the Company continued to maintain valuation allowances in North America, EMEA and Asia.

Enterprise-Wide Information

Enterprise-Wide Information	3 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Enterprise-Wide Information	(15) Enterprise-Wide Information The Company is a global provider of ultra-broadband network access solutions and communications platforms deployed by advanced Tier 1, national and regional service providers and enterprise customers. There are no segment managers who are held accountable for operations, operating results and plans for levels or components below the Company unit level. Accordingly, the Company is considered to be in a single operating segment. The Company’s chief operating decision maker is the Company’s Chief Executive Officer, who reviews financial information presented on a consolidated basis accompanied with disaggregated revenues by geographic region for purposes of making operating decisions and assessing financial performance. The Company attributes revenue from customers to individual countries based on location shipped. Refer to Note 1(e) Disaggregation of Revenue for the required disclosures on geographical concentrations and revenues by source. The Company's property, plant and equipment, net of accumulated depreciation, were located in the following geographical areas (in thousands) as of March 31, 2023 and December 31, 2022: March 31, 2023 December 31, 2022 United States $ 3,870 $ 5,725 Korea 2,440 2,706 Japan 619 644 Canada — 157 Germany 88 110 Other 118 136 $ 7,135 $ 9,478

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	(b) Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. GAAP for interim financial information and with the instructions to Form 10-Q and Article 3 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These financial statements include the accounts of the Company and its wholly owned subsidiaries. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission (“SEC”) on March 10, 2023. For a complete description of what the Company believes to be the critical accounting policies and estimates used in the preparation of its unaudited condensed consolidated financial statements, refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. All intercompany transactions and balances have been eliminated in consolidation. Certain prior-year amounts have been reclassified to conform to the current-quarter presentation. The unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) that, in the opinion of management, are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the current interim period are not necessarily indicative of results to be expected for the current year or any other period.
Risks and Uncertainties	(c) Risks and Uncertainties The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. GAAP, assuming the Company will continue as a going concern. We continue to be exposed to macroeconomic pressures in the post-COVID-19 environment, including concerns about energy costs, geopolitical issues, inflation, the availability and cost of credit, business and consumer confidence, and unemployment. We have seen improvement in our supply chain in 2023 as supply chain pricing, freight and logistics costs, product and component availability, and extended lead-times which were a challenge in 2021 and 2022 begin to alleviate in 2023 as the world economy recovers from the COVID-19 pandemic. We expect elevated costs for components and expedite fees to further improve throughout 2023. We conduct significant business in South Korea, Japan, Vietnam, India, Spain, and Canada, as well as in other countries in Europe, Asia-Pacific, Middle East and Latin America, all of which subject us to foreign currency exchange rate risk. The local currencies of our significant foreign subsidiaries are the South Korean Won ("KRW"), Japanese Yen ("JPY"), Euro ("EUR), and Pound Sterling ("GBP"). Revenues and operating expenses are typically denominated in the local currency of each country and result from transactions by our operations in these countries. However, a significant portion of our international cost of sales is denominated in the U.S. Dollar (“USD”). During 2022, the USD appreciated significantly against the KRW, JPY, EUR and GBP which reduced the translated revenues, cost of sales and operating expenses transacted in local currencies, but not the USD based cost of sales, resulting in compressed margins and lower profitability. Late in 2022, exchange rates for these currencies abated somewhat, but the exchange rates for the KRW and JPY remain elevated compared to historical rates. As of March 31, 2023, the Company's debt obligation under the Term Loan was $23.7 million, net of unamortized issuance cost of $0.4 million, of which $1.3 million is scheduled for payment in the next 12 months. Due to the ongoing risk of non-compliance in the next 12 months we continue to classify the entire amount as a current liability. We are currently in discussion with the lenders to amend the debt agreement to mitigate the risk of non-compliance. In addition to negotiating for revised financial covenants, we continue to focus on cost management, operating efficiency and efficient discretionary spending. Management is actively taking measures to enhance profitability and liquidity, including reducing the Company’s cost structure and cash outflows, including its investment in inventory, and managing receivable balances through aggressive collection efforts and tighter customers payment terms.These plans are not completely within the Company’s control, as some actions are dependent on the Company’s lenders, vendors and customers. However, the Company believes that it will maintain liquidity in the next 12 months to support its operations.
Use of Estimates	(d) Use of EstimatesThe preparation of the unaudited condensed consolidated financial statements in conformity with U.S. 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 unaudited condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ materially from those estimates.
Concentration of Risk	(f) Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents and restricted cash, accounts receivables, and contract assets. Cash, cash equivalents and restricted cash consist of financial deposits and money market accounts that are principally held with various domestic and international financial institutions with high credit standing. The Company’s customers include competitive and incumbent local exchange carriers, competitive access providers, internet service providers, wireless carriers and resellers serving these markets. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. Allowances are maintained for potential doubtful accounts based upon the expected collectability of accounts receivable using historical loss rates adjusted for customer-specific factors and current economic conditions. The Company determines historical loss rates on a rational and systematic basis. The Company performs periodic assessments of its customers’ liquidity and financial condition through analysis of information obtained from credit rating agencies, financial statement review and historical and current collection trends.
Business Combinations	(g) Business Combinations The Company allocates the fair value of purchase consideration to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. When determining the fair values of assets acquired and liabilities assumed, management makes significant estimates and assumptions, especially with respect to intangible assets and certain tangible assets such as inventory. Critical estimates in valuing certain tangible and intangible assets include but are not limited to future expected cash flows from the underlying assets and discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. Assets acquired and liabilities assumed are generally measured at their acquisition-date fair values. If the initial accounting for a business combination is incomplete by the end of the reporting period in which the combination occurs, the Company reports provisional amounts for the items for which the accounting is incomplete. Those provisional amounts are adjusted during the measurement period (which cannot exceed one year from the acquisition date), or additional assets or liabilities are recognized, to reflect new information obtained about facts and circumstances that existed as of the acquisition date that, if known, would have affected the amounts recognized as of that date. When the consideration transferred by the Company in a business combination includes a contingent consideration arrangement, the contingent consideration is measured at its acquisition-date fair value and included as part of the total consideration transferred in a business combination. Changes in fair value of the contingent consideration that qualify as measurement period adjustments are made retrospectively, with corresponding adjustments against goodwill. Changes in the fair value of the contingent consideration that do not qualify as measurement period adjustments are made in the current period, with corresponding adjustments recognized in earnings.
Restructuring and Other Charges	(h) Restructuring and Other Charges From time to time, the Company takes actions to align its workforce, facilities and operating costs with perceived market opportunities, business strategies and changes in market and business conditions. The Company recognizes a liability for the cost associated with an exit or disposal activity in the period in which the liability is incurred, except for one-time employee termination benefits, which are measured at the communication date and recognized ratably over the required service period, if any.
Recent Accounting Pronouncements	(i) Recent Accounting Pronouncements In October 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which requires the Company to apply ASC 606, Revenue from Contracts with Customers, to recognize and measure contract assets and contract liabilities from contracts with customers acquired in a business combination. Before the update such balances were measured and recognized at fair value on the acquisition date. The ASU is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods. The Company adopted these requirements prospectively, effective on the first day of the second quarter of year 2022. There was no material impact on our consolidated financial statements on the adoption date. In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires the Company to measure and recognize expected credit losses for financial assets held and not accounted for at fair value through net income. In November 2018, April 2019 and May 2019, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, and ASU No. 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief, which provided additional implementation guidance on the previously issued ASU. The Company adopted the updated guidance on January 1, 2022, utilizing the modified retrospective transition method and recorded a cumulative-effect adjustment of $0.4 million to retained earnings.

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Revenues by Source	The following table presents revenues by product technology (in thousands): Three Months Ended March 31, 2023 2022 Access Networking Infrastructure $ 79,459 $ 72,462 Cloud Software & Services 11,353 4,578 Total $ 90,812 $ 77,040
Schedule of Information Revenues by Geographical Concentration	The following table present revenues by geographical concentration (in thousands): Three Months Ended March 31, 2023 2022 Americas $ 24,855 $ 23,061 Europe, Middle East, Africa 19,182 18,649 Asia 46,775 35,330 Total $ 90,812 $ 77,040
Schedule of Allowances for Doubtful Accounts	Activity under the Company’s allowance for doubtful accounts consists of the following (in thousands): Three Months Ended March 31, 2023 2022 Balance at beginning of period $ 16,184 $ 17,735 Charged to expense, net of recoveries (184) (752) Utilization and write off — — Cumulative effect of ASC 326 adoption — 401 Foreign exchange impact 87 (326) Balance at end of period $ 16,087 $ 17,058

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Summary of Provisional Estimated Fair Values of Assets Acquired and Liabilities Assumed	The following summarizes the final fair values of the assets acquired and liabilities assumed at the date of the ASSIA Acquisition (in thousands): Allocation of purchase consideration Cash and cash equivalents $ 203 Accounts receivable 2,322 Other assets 407 Right-of-use assets 2,172 Property, plant and equipment 232 Intangible assets 30,200 Accounts payable (75) Contract liabilities (19,550) Operating lease liabilities (2,612) Accrued and other liabilities (756) Goodwill 13,807 Total purchase consideration $ 26,350
Schedule of Estimated Fair Value and Useful Lives of Identifiable Intangible Assets	The following table represents the final estimated fair value and useful lives of identifiable intangible assets acquired (estimated fair value in thousands): Estimated Estimated Intangible assets acquired Customer relationships $ 18,600 15 years Customer backlog 5,100 10 years Developed technology 6,200 5 - 7 years Tradenames 300 10 years Total intangible assets $ 30,200

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Reconciliation of Level 3 Contingent Liability	The following table reconciles the beginning and ending balances of the Company’s Level 3 contingent liability (in thousands): Three Months Ended March 31, 2023 2022 Balance at beginning of period $ 1,156 $ 2,121 Cash payments — — Net change in fair value 27 51 Balance at end of period $ 1,183 $ 2,172

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Schedule of Inventories	Inventories March 31, 2023 December 31, 2022 Raw materials $ 35,870 $ 37,354 Work in process 699 1,050 Finished goods 33,153 40,109 Total inventories $ 69,722 $ 78,513
Schedule of Property, Plant and Equipment, Net	Property, plant and equipment March 31, 2023 December 31, 2022 Property, plant and equipment, net: Machinery and equipment $ 12,971 $ 17,214 Leasehold improvements 2,440 5,683 Computers and software 4,608 4,713 Furniture and fixtures 2,108 1,748 Construction in progress and other 1,358 1,264 23,485 30,622 Less: accumulated depreciation and amortization (16,285) (21,062) Less: government grants (65) (82) Total property, plant and equipment, net $ 7,135 $ 9,478
Summary of Product Warranty Liability	The following table summarizes the activity related to the product warranty liability: Three Months Ended March 31, 2023 2022 Balance at beginning of period $ 1,896 $ 1,981 Charged to cost of revenue 70 121 Claims and settlements (113) (149) Foreign exchange impact 21 (17) Balance at end of period $ 1,874 $ 1,936
Summary of Contract Assets and Contract Liabilities Related to Contracts with Customers	The opening and closing balances of current and long-term contract assets and contract liabilities related to contracts with customers are as follows: Contract Contract December 31, 2022 $ 576 $ 29,641 March 31, 2023 $ 605 $ 29,225

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table summarizes the activity related to goodwill (in thousands): March 31, 2023 2022 Balance at beginning of period, gross $ 20,955 $ 7,148 Accumulated impairment at beginning of period (1,003) (1,003) Goodwill from acquisitions — — Foreign exchange impact — — Balance at end of period $ 19,952 $ 6,145
Schedule of Intangible Assets	Intangible assets consisted of the following (in thousands): March 31, 2023 Gross Carrying Accumulated Net Customer relationships $ 24,331 $ (5,451) $ 18,880 Customer backlog 5,100 (723) 4,377 Developed technology 11,207 (4,822) 6,385 In-process research and development 890 (385) 505 Tradenames 300 (25) 275 Total intangible assets, net $ 41,828 $ (11,406) $ 30,422 December 31, 2022 Gross Carrying Accumulated Net Customer relationships $ 24,330 $ (4,759) $ 19,571 Customer backlog 5,100 (506) 4,594 Developed technology 11,207 (4,463) 6,744 In-process research and development 890 (340) 550 Tradenames 300 (17) 283 Total intangible assets, net $ 41,827 $ (10,085) $ 31,742
Future Amortization Expense of Intangible Assets	The following table presents the future amortization expense of the Company’s intangible assets as of March 31, 2023 (in thousands): Remainder of 2023 $ 3,962 2024 5,283 2025 5,278 2026 4,095 2027 3,143 Thereafter 8,661 Total $ 30,422

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Debt	The following table summarizes the Company’s debt (in thousands): March 31, 2023 December 31, 2022 JPMorgan Term Loan, long-term $ — $ — JPMorgan Term Loan, current portion 24,063 24,375 Unamortized debt issuance costs (403) (302) Long-term debt, including current portion $ 23,660 $ 24,073 JPMorgan Revolving Credit Facility $ 12,000 $ 4,000 Industrial Bank of Korea Loan 919 — DNI Related Party Loan 3,827 5,706 Short-term debt and credit facilities $ 16,746 $ 9,706 Total Debt $ 40,406 $ 33,779
Schedule of Future Principal Maturities of Term Loan	The future principal maturities of the Term Loan for each of the next five years are as follows (in thousands): Remainder of 2023 $ 938 2024 1,563 2025 1,875 2026 2,188 2027 17,499 Total $ 24,063

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table sets forth payment guarantees of the Company's obligations as of March 31, 2023 that have been provided by Dasan Networks, Inc. ("DNI"). DNI owns approximately 29.2% of the outstanding shares of the Company's common stock. The amount guaranteed exceeds the principal amounts of outstanding obligations due to collateral requirements by the banks. Guarantor Amount Guaranteed Description of Obligations Guaranteed Dasan Networks, Inc. $ 4,422 Payment guarantee to Industrial Bank of Korea Dasan Networks, Inc. 3,068 Payment guarantee to Shinhan Bank $ 7,490 Sales, cost of revenue, operating expense, interest expense and other expenses to and from related parties were as follows (in thousands) for the three months ended March 31, 2023 and 2022: Three Months Ended March 31, 2023 Counterparty Sales Cost of Operating Expense Interest Other Dasan Networks, Inc. $ 153 $ 128 $ 294 $ 79 $ 16 Three Months Ended March 31, 2022 Counterparty Sales Cost of Operating Expense Interest Other Dasan Networks, Inc. $ 198 $ 177 $ 407 $ — $ 17 Balances of receivables and payables arising from sales and purchases of goods and services with related parties as of March 31, 2023 and December 31, 2022 were included in the following balance sheet captions on the unaudited condensed consolidated balance sheets, as follows (in thousands): As of March 31, 2023 Counterparty Account Other Loans Payable Accounts Accrued and other liabilities Dasan Networks, Inc. $ 224 $ — $ 3,827 $ 895 $ 212 As of December 31, 2022 Counterparty Account Other Loans Payable Accounts Accrued and other liabilities Dasan Networks, Inc. $ 943 $ 123 $ 5,706 $ 1,019 $ 483

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Net Income (Loss) per Share	The following table is a reconciliation of the numerator and denominator in the basic and diluted net income (loss) per share calculation (in thousands, except per share data) for the three months ended March 31, 2023, and 2022: Three months ended March 31, 2023 2022 Net income (loss) $ (17,135) $ (3,048) Weighted average number of shares outstanding: Basic 31,045 27,530 Effect of dilutive securities: Stock options, restricted stock units and share awards — — Diluted 31,045 27,530 Net income (loss) per share: Basic $ (0.55) $ (0.11) Diluted $ (0.55) $ (0.11)
Potential Common Stock Not Included Diluted Net Income (Loss) Per Share Calculation	The following table sets forth potential common stock that is not included in the diluted net income (loss) per share calculation above because their effect would be anti-dilutive for the periods indicated (in thousands): Three months ended March 31, 2023 2022 Outstanding stock options 563 939 Unvested restricted stock units 500 278

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Maturity of Operating Lease Liabilities	The following table presents the maturity of the Company’s operating lease liabilities as of March 31, 2023 (in thousands): Remainder of 2023 $ 4,209 2024 5,131 2025 3,575 2026 2,232 2027 1,121 Thereafter 693 Total operating lease payments 16,961 Less: imputed interest (1,603) Total operating lease liabilities $ 15,358

Enterprise-Wide Information (Ta

Enterprise-Wide Information (Tables)	3 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Property, Plant and Equipment, Net of Accumulated Depreciation	The Company's property, plant and equipment, net of accumulated depreciation, were located in the following geographical areas (in thousands) as of March 31, 2023 and December 31, 2022: March 31, 2023 December 31, 2022 United States $ 3,870 $ 5,725 Korea 2,440 2,706 Japan 619 644 Canada — 157 Germany 88 110 Other 118 136 $ 7,135 $ 9,478

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2022	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Billed amount under agreement							$ 59,000
Amount of payments collected					$ 41,700
Accounts receivable recovered			$ 2,500
Allowance for doubtful accounts	$ 13,100
Cumulative adjustment to retained earnings	127,885	$ 130,949	131,907	$ 142,732	131,907
Accumulated deficit
Significant Accounting Policies [Line Items]
Cumulative adjustment to retained earnings	$ (141,966)	$ (90,448)	(86,999)	$ (124,831)	(86,999)
Cumulative Effect, Period of Adoption, Adjustment
Significant Accounting Policies [Line Items]
Cumulative adjustment to retained earnings			(401)		(401)
Cumulative Effect, Period of Adoption, Adjustment | Accumulated deficit
Significant Accounting Policies [Line Items]
Cumulative adjustment to retained earnings			$ (401)		$ (401)	$ 400
Customer Concentration Risk | Sales Revenue, Net | Customer One
Significant Accounting Policies [Line Items]
Concentration risk, percentage	13%	13%
Customer Concentration Risk | Sales Revenue, Net | Customer Two
Significant Accounting Policies [Line Items]
Concentration risk, percentage	13%	12%
Geographic Concentration Risk | Accounts receivable | Foreign Countries
Significant Accounting Policies [Line Items]
Concentration risk, percentage	86%			86%

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Schedule of Revenues by Source (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Net revenue	$ 90,812	$ 77,040
Access Networking Infrastructure
Disaggregation Of Revenue [Line Items]
Net revenue	79,459	72,462
Cloud Software & Services
Disaggregation Of Revenue [Line Items]
Net revenue	$ 11,353	$ 4,578

Organization and Summary of S_6

Organization and Summary of Significant Accounting Policies - Schedule of Information Revenues by Geographical Concentration (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Net revenue	$ 90,812	$ 77,040
Americas
Disaggregation Of Revenue [Line Items]
Net revenue	24,855	23,061
Europe, Middle East, Africa
Disaggregation Of Revenue [Line Items]
Net revenue	19,182	18,649
Asia
Disaggregation Of Revenue [Line Items]
Net revenue	$ 46,775	$ 35,330

Organization and Summary of S_7

Organization and Summary of Significant Accounting Policies - Schedule of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 16,184	$ 17,735
Charged to expense, net of recoveries	(184)	(752)
Utilization and write off	0	0
Foreign exchange impact	87	(326)
Balance at end of period	16,087	17,058
Cumulative effect of ASC 326 adoption
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 0	$ 401

Business Combinations - Additio

Business Combinations - Additional Information (Details) $ in Thousands, home in Millions				1 Months Ended		3 Months Ended
	May 27, 2022 USD ($)	Mar. 03, 2021 USD ($)	Feb. 05, 2021 USD ($)	Oct. 31, 2022 USD ($)	Apr. 30, 2021 USD ($)	Mar. 31, 2023 USD ($) home	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)
Business Acquisition [Line Items]
Goodwill						$ 19,952		$ 19,952	$ 6,145
Optelian
Business Acquisition [Line Items]
Goodwill			$ 1,900
Optelian | Optelian Products
Business Acquisition [Line Items]
Purchase price			7,500
Held back amount							$ 300
Contingent consideration			$ 1,900
RIFT Inc
Business Acquisition [Line Items]
Purchase price		$ 500
Goodwill		$ 200
Held back amount released					$ 200
ASSIA
Business Acquisition [Line Items]
Number of homes connected globally | home						125
Purchase price	$ 25,000
Held back amount	$ 2,500
Term after close for release of holdback amount	13 months
Additional consideration paid				$ 1,350
Goodwill	$ 13,807

Business Combinations - Summary

Business Combinations - Summary of Provisional Estimated Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	May 27, 2022	Mar. 31, 2022
Provisional allocation of purchase consideration
Goodwill	$ 19,952	$ 19,952		$ 6,145
ASSIA
Provisional allocation of purchase consideration
Cash and cash equivalents			$ 203
Accounts receivable			2,322
Other assets			407
Right-of-use assets			2,172
Property, plant and equipment			232
Intangible assets			30,200
Accounts payable			(75)
Contract liabilities			(19,550)
Operating lease liabilities			(2,612)
Accrued and other liabilities			(756)
Goodwill			13,807
Total purchase consideration			$ 26,350

Business Combinations - Schedul

Business Combinations - Schedule of Estimated Fair Value and Useful Lives of Identifiable Intangible Assets (Details) - ASSIA $ in Thousands	May 27, 2022 USD ($)
Business Acquisition [Line Items]
Estimated fair value	$ 30,200
Customer relationships
Business Acquisition [Line Items]
Estimated fair value	$ 18,600
Estimated useful life	15 years
Customer backlog
Business Acquisition [Line Items]
Estimated fair value	$ 5,100
Estimated useful life	10 years
Developed technology
Business Acquisition [Line Items]
Estimated fair value	$ 6,200
Developed technology | Minimum
Business Acquisition [Line Items]
Estimated useful life	5 years
Developed technology | Maximum
Business Acquisition [Line Items]
Estimated useful life	7 years
Tradenames
Business Acquisition [Line Items]
Estimated fair value	$ 300
Estimated useful life	10 years

Fair Value Measurement - Schedu

Fair Value Measurement - Schedule of Reconciliation of Level 3 Contingent Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 1,156	$ 2,121
Cash payments	0	0
Net change in fair value	27	51
Balance at end of period	$ 1,183	$ 2,172

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 28,892	$ 34,347	$ 34,160
Long term restricted cash	100	200
Outside U.S.
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	14,100	13,600
Within U.S.
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 16,800	$ 24,900

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials	$ 35,870	$ 37,354
Work in process	699	1,050
Finished goods	33,153	40,109
Total inventories	$ 69,722	$ 78,513

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Balance Sheet Details [Line Items]
Standard product warranty, term	1 year
Extended product warranty, term (up to)	5 years
Contract with customer, liability, revenue recognized	$ 7.4
Contract cost deferred	0.5		$ 1
Amortization related to contract cost deferred	$ 0.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Balance Sheet Details [Line Items]
Percentage of revenue expected to recognize	75%
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Balance Sheet Details [Line Items]
Percentage of revenue expected to recognize	25%
Revenue, remaining performance obligation, expected timing of satisfaction, period
Property, Plant and Equipment
Balance Sheet Details [Line Items]
Depreciation and amortization associated with property, plant and equipment	$ 1.2	$ 0.8

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, plant and equipment, net:
Property, plant and equipment, gross	$ 23,485	$ 30,622
Less: accumulated depreciation and amortization	(16,285)	(21,062)
Less: government grants	(65)	(82)
Total property, plant and equipment, net	7,135	9,478
Machinery and equipment
Property, plant and equipment, net:
Property, plant and equipment, gross	12,971	17,214
Leasehold improvements
Property, plant and equipment, net:
Property, plant and equipment, gross	2,440	5,683
Computers and software
Property, plant and equipment, net:
Property, plant and equipment, gross	4,608	4,713
Furniture and fixtures
Property, plant and equipment, net:
Property, plant and equipment, gross	2,108	1,748
Construction in progress and other
Property, plant and equipment, net:
Property, plant and equipment, gross	$ 1,358	$ 1,264

Balance Sheet Details - Summary

Balance Sheet Details - Summary of Product Warranty Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of period	$ 1,896	$ 1,981
Charged to cost of revenue	70	121
Claims and settlements	(113)	(149)
Foreign exchange impact	21	(17)
Balance at end of period	$ 1,874	$ 1,936

Balance Sheet Details - Summa_2

Balance Sheet Details - Summary of Contract Assets and Contract Liabilities Related to Contracts with Customers (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Contract assets	$ 605	$ 576
Contract liabilities	$ 29,225	$ 29,641

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Balance at beginning of period, gross			$ 20,955	$ 7,148
Accumulated impairment at beginning of period			$ (1,003)	$ (1,003)
Foreign exchange impact	$ 0	$ 0
Balance at end of period	19,952	6,145
Optelian and RIFT Acquisitions
Goodwill [Roll Forward]
Goodwill from acquisitions		$ 0
ASSIA
Goodwill [Roll Forward]
Goodwill from acquisitions	$ 0

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 41,828	$ 41,827
Accumulated Amortization	(11,406)	(10,085)
Total	30,422	31,742
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	24,331	24,330
Accumulated Amortization	(5,451)	(4,759)
Total	18,880	19,571
Customer backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,100	5,100
Accumulated Amortization	(723)	(506)
Total	4,377	4,594
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	11,207	11,207
Accumulated Amortization	(4,822)	(4,463)
Total	6,385	6,744
In-process research and development
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	890	890
Accumulated Amortization	(385)	(340)
Total	505	550
Tradenames
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	300	300
Accumulated Amortization	(25)	(17)
Total	$ 275	$ 283

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 1,271	$ 294

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Future Amortization Expense of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2023	$ 3,962
2024	5,283
2025	5,278
2026	4,095
2027	3,143
Thereafter	8,661
Total	$ 30,422	$ 31,742

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) $ in Thousands, ₩ in Billions	Mar. 31, 2023 USD ($)	Mar. 30, 2023 USD ($)	Mar. 30, 2023 KRW (₩)	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
JPMorgan Term Loan, long-term	$ 0			$ 0
JPMorgan Term Loan, current portion	23,660			24,073
DNI Related Party Loan	3,827			5,706
Short-term debt and credit facilities	16,746			9,706
Total Debt	40,406			33,779
Revolving Credit Agreement
Debt Instrument [Line Items]
JPMorgan Revolving Credit Facility				4,000
Industrial Bank of Korea Loan
Debt Instrument [Line Items]
Industrial Bank of Korea Loan	919	$ 900	₩ 1.2	0
Secured Debt | Second Amendment to Credit Agreement
Debt Instrument [Line Items]
JPMorgan Term Loan, long-term	0			0
JPMorgan Term Loan, current portion	24,063			24,375
Unamortized debt issuance costs	(403)			(302)
Long-term debt, including current portion	23,660			$ 24,073
Line of Credit | Second Amendment to Credit Agreement
Debt Instrument [Line Items]
Long-term debt, including current portion	23,700
Line of Credit | Second Amendment to Credit Agreement | Revolving Credit Agreement
Debt Instrument [Line Items]
JPMorgan Revolving Credit Facility	$ 12,000

Debt - Additional Information (

Debt - Additional Information (Details) ₩ in Billions

1 Months Ended

3 Months Ended

May 08, 2023 USD ($) Rate

Feb. 15, 2023 USD ($) Rate

May 27, 2022 USD ($)

Oct. 31, 2022 USD ($)

Mar. 31, 2023 USD ($)

Jun. 15, 2023 USD ($)

Mar. 31, 2023 KRW (₩)

Mar. 30, 2023 USD ($) customer

Mar. 30, 2023 KRW (₩) customer

Dec. 31, 2022 USD ($)

Oct. 31, 2022 KRW (₩)

Feb. 09, 2022 USD ($)

Line Of Credit Facility [Line Items]

Minimum EBITDA for the fiscal quarter ending March 31, 2023

$ (1,000,000)

Minimum EBITDA for the fiscal quarter ending June 30, 2023

$ 1

DNI related party loan

$ 3,827,000

$ 5,706,000

Leverage Ratio Exceeds 2.5

Line Of Credit Facility [Line Items]

Commitment fee percentage on unused capacity

0.40%

Accounts receivable

Line Of Credit Facility [Line Items]

Number of customers included in accounts receivable collateral | customer

2

2

Second Amendment to Credit Agreement | Line of Credit

Line Of Credit Facility [Line Items]

Credit facility, current borrowing capacity

16,800,000

Maximum leverage ratio through September 30, 2023 | Rate

250%

Minimum fixed charge coverage ratio until December 31, 2023 | Rate

125%

Minimum required liquidity, fiscal quarter ending March 31, 2023

$ 30,000,000

Minimum required liquidity, fiscal quarter ending June 30, 2023 and September 30, 2023

35,000,000

Minimum required liquidity, any time until September 30, 2023

$ 20,000,000

Leverage ratio (in excess of) | Rate

250%

Debt obligations

23,700,000

Unamortized issuance costs

400,000

Payments due in the next 12 months

1,300,000

Letters of credit issued

(1,200,000)

Portion of long term debt not in compliance with covenants

22,800,000

23,100,000

Second Amendment to Credit Agreement | Adjusted Term SOFR Rate | Line of Credit | Leverage Ratio Exceeds 2.5

Line Of Credit Facility [Line Items]

Margins for borrowings

4%

Second Amendment to Credit Agreement | Prime Rate | Line of Credit | Leverage Ratio Exceeds 2.5

Line Of Credit Facility [Line Items]

Margins for borrowings

3%

November 2022 DNI Loan | Investor | Short-Term Debt

Line Of Credit Facility [Line Items]

DNI related party loan

$ 5,000,000

₩ 7.2

Interest rate on related party loan

6%

February 2023 DNI Loan | Inventories

Line Of Credit Facility [Line Items]

Collateral for related party loans

26,800,000

₩ 35

February 2023 DNI Loan | Accounts receivable

Line Of Credit Facility [Line Items]

Collateral for related party loans

12,400,000

16.2

February 2023 DNI Loan | Investor

Line Of Credit Facility [Line Items]

DNI related party loan

4,100,000

February 2023 DNI Loan | Investor | Short-Term Debt

Line Of Credit Facility [Line Items]

DNI related party loan

$ 3,800,000

5

Interest rate on related party loan

7%

February 2023 DNI Loan | Minimum | Inventories

Line Of Credit Facility [Line Items]

Collateral for related party loans

$ 7,700,000

₩ 10

Industrial Bank of Korea Loan

Line Of Credit Facility [Line Items]

Industrial Bank of Korea loan

$ 919,000

$ 900,000

₩ 1.2

$ 0

Interest rate

6.30%

6.30%

Third Amendment to Credit Agreement | Line of Credit | Subsequent Event

Line Of Credit Facility [Line Items]

Minimum EBITDA for the fiscal quarter ending March 31, 2023

$ 1,000,000

Leverage ratio (in excess of) | Rate

250%

Borrowing base decrease through June 30, 2023

$ 5,000,000

Additional borrowing base decrease after June 30, 2023

$ 5,000,000

Third Amendment to Credit Agreement | Adjusted Term SOFR Rate | Line of Credit | Leverage Ratio Exceeds 2.5 | Subsequent Event

Line Of Credit Facility [Line Items]

Margins for borrowings

4.50%

Third Amendment to Credit Agreement | Prime Rate | Line of Credit | Leverage Ratio Exceeds 2.5 | Subsequent Event

Line Of Credit Facility [Line Items]

Margins for borrowings

3.50%

JPMorgan Credit Facility | Letter of Credit

Line Of Credit Facility [Line Items]

Maximum borrowing amount

$ 15,000,000

Revolving Credit Agreement

Line Of Credit Facility [Line Items]

Maximum borrowing amount

$ 30,000,000

Revolving Credit Agreement | Third Amendment to Credit Agreement | Line of Credit | Subsequent Event | Forecast

Line Of Credit Facility [Line Items]

Maximum borrowing amount

$ 25,000,000

Revolving Credit Agreement | JPMorgan Credit Facility

Line Of Credit Facility [Line Items]

Maximum borrowing amount

30,000,000

Credit facility, current borrowing capacity

$ 10,000,000

Amendment to Credit Agreement

Line Of Credit Facility [Line Items]

Maximum permitted leverage ratio through September 30, 2022

3

Maximum permitted leverage ratio through September 30, 2023

2.50

Maximum permitted leverage ratio after September 30 2023

2

Minimum permitted fixed charge coverage ratio

1.25

Amendment to Credit Agreement | Minimum

Line Of Credit Facility [Line Items]

Commitment fee percentage on unused capacity

0.25%

Amendment to Credit Agreement | Maximum

Line Of Credit Facility [Line Items]

Commitment fee percentage on unused capacity

0.35%

Amendment to Credit Agreement | Adjusted Term SOFR Rate | Minimum

Line Of Credit Facility [Line Items]

Margins for borrowings

3%

Amendment to Credit Agreement | Adjusted Term SOFR Rate | Maximum

Line Of Credit Facility [Line Items]

Margins for borrowings

3.50%

Amendment to Credit Agreement | Prime Rate | Minimum

Line Of Credit Facility [Line Items]

Margins for borrowings

2%

Amendment to Credit Agreement | Prime Rate | Maximum

Line Of Credit Facility [Line Items]

Margins for borrowings

2.50%

Amendment to Credit Agreement | Letter of Credit | Minimum

Line Of Credit Facility [Line Items]

Commitment fee percentage

3%

Amendment to Credit Agreement | Letter of Credit | Maximum

Line Of Credit Facility [Line Items]

Commitment fee percentage

3.50%

Amendment to Credit Agreement | Term Loan

Line Of Credit Facility [Line Items]

Maximum borrowing amount

$ 25,000,000

Debt - Schedule of Future Princ

Debt - Schedule of Future Principal Maturities of Term Loan (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Debt Disclosure [Abstract]
Remainder of 2023	$ 938
2024	1,563
2025	1,875
2026	2,188
2027	17,499
Total	$ 24,063

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	8.30%
Defined benefit plan, accumulated benefit obligation	$ 11.1		$ 11
Periodic benefit costs	0.1	$ 0.1
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, insurance contract amount	2.5		$ 2.5
United States
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	0.3	0.2
Korea
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	$ 0.3	$ 0.3

Restructuring and Other Charg_2

Restructuring and Other Charges - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Estimated percentage of positions eliminated	66.67%
Restructuring costs	$ 3,500,000
Accelerated depreciation	400,000
Relocate Manufacturing Functions | Gmbh and Optelian Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring and related costs	0	$ 400,000
Freight and Expedite Fees | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	1,000,000
Facility and Labor Costs | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	800,000
Employee Severance | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	300,000
Restructuring liability	600,000
Inventory Write-Off | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	500,000
Other Restructuring | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	500,000
Facility Impairment Costs | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	300,000
Software and Software Development Costs | Seminole Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 400,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) $ in Thousands, ₩ in Billions	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 KRW (₩)	Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items]
DNI related party loan	$ 3,827			$ 5,706
Operating lease liability	15,358
Right-of-use assets from operating leases	11,971			12,606
Investor | February 2023 DNI Loan
Related Party Transaction [Line Items]
DNI related party loan	4,100
Investor | February 2023 DNI Loan | Short-Term Debt
Related Party Transaction [Line Items]
DNI related party loan	$ 3,800		₩ 5
DASAN | Investor
Related Party Transaction [Line Items]
License fee as a percent of annual sales	0.40%		0.40%
Royalty expense	$ 200	$ 100
DNI
Related Party Transaction [Line Items]
Operating lease cost	100	$ 200
DNI | Investor
Related Party Transaction [Line Items]
Operating lease liability	1,600			1,700
Right-of-use assets from operating leases	$ 1,600			$ 1,700
Guarantee fee, percent	0.90%
DZS, Inc | Investor | DASAN
Related Party Transaction [Line Items]
DNI direct ownership interest	29.20%		29.20%

Related Party Transactions - In

Related Party Transactions - Indebtedness and Other Obligations Payment Guarantees (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Related Party Transaction [Line Items]
Amount Guaranteed	$ 7,490
Payment guarantee to Industrial Bank of Korea
Related Party Transaction [Line Items]
Amount Guaranteed	4,422
Payment guarantee to Shinhan Bank
Related Party Transaction [Line Items]
Amount Guaranteed	$ 3,068

Related Party Transactions - Sa

Related Party Transactions - Sales and Purchases To and From Related Parties (Details) - DASAN - Investor - Sales and Purchases to and from Related Parties - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Related Party Transaction [Line Items]
Sales	$ 153	$ 198
Cost of revenue	128	177
Operating Expense	294	407
Interest expense	79	0
Other expenses	$ 16	$ 17

Related Party Transactions - Ba

Related Party Transactions - Balances of Receivables and Payables with Related Parties (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Loans Payable	$ 3,827	$ 5,706
DASAN | Receivables and Payables With Related Parties
Related Party Transaction [Line Items]
Account receivables	224	943
Other receivables	0	123
Loans Payable	3,827	5,706
Accounts payable	895	1,019
Accrued and other liabilities	$ 212	$ 483

Net Income (Loss) Per Share - R

Net Income (Loss) Per Share - Reconciliation of Basic and Diluted Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Net income (loss)	$ (17,135)	$ (3,048)
Weighted average number of shares outstanding:
Basic (in shares)	31,045,000	27,530,000
Effect of dilutive securities:
Stock options, restricted stock units and share awards (in shares)	0	0
Diluted (in shares)	31,045,000	27,530,000
Net income (loss) per share:
Basic (in dollar per share)	$ (0.55)	$ (0.11)
Diluted (in dollar per share)	$ (0.55)	$ (0.11)

Net Income (Loss) Per Share - A

Net Income (Loss) Per Share - Antidilutive Securities Excluded from Computation of Earning Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Outstanding stock options
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of loss per share calculation (in shares)	563	939
Unvested restricted stock units
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of loss per share calculation (in shares)	500	278

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Operating lease expense	$ 1	$ 1.2

Leases - Maturity of Operating

Leases - Maturity of Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Leases [Abstract]
Remainder of 2023	$ 4,209
2024	5,131
2025	3,575
2026	2,232
2027	1,121
Thereafter	693
Total operating lease payments	16,961
Less: imputed interest	(1,603)
Total operating lease liabilities	$ 15,358

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) ₨ in Millions, $ in Millions	3 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 INR (₨)	Mar. 31, 2022 USD ($)	Mar. 31, 2022 INR (₨)	Mar. 31, 2023 USD ($)
Guarantee Obligations [Line Items]
Underpaid duties			$ 3.6	₨ 299.6
Subsequent Event | Forecast
Guarantee Obligations [Line Items]
Underpaid duties	$ 4.7	₨ 389.3
Performance Guarantee
Guarantee Obligations [Line Items]
Guarantor obligations					$ 15.6

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 1,843	$ (1,333)
Income (loss) before income taxes	$ (15,292)	$ (4,381)

Enterprise-Wide Information - P

Enterprise-Wide Information - Property, Plant and Equipment, Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 7,135	$ 9,478
United States
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	3,870	5,725
Korea
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	2,440	2,706
Japan
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	619	644
Canada
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	0	157
Germany
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	88	110
Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 118	$ 136