v3.26.1
REVENUE RECOGNITION - Schedule of Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
REVENUE RECOGNITION        
Total revenue $ 192,340 $ 220,583 $ 354,946 $ 401,862
United States        
REVENUE RECOGNITION        
Total revenue 89,367 116,222 161,945 198,917
Europe, Middle East and Africa        
REVENUE RECOGNITION        
Total revenue 49,092 52,113 88,162 97,612
Asia Pacific        
REVENUE RECOGNITION        
Total revenue 42,638 41,752 83,565 84,931
Other        
REVENUE RECOGNITION        
Total revenue 11,243 10,496 21,274 20,402
Product revenue        
REVENUE RECOGNITION        
Total revenue 95,560 115,057 163,674 197,048
Product revenue | Cloud and Edge        
REVENUE RECOGNITION        
Total revenue 37,722 56,112 63,981 87,973
Product revenue | IP Optical Networks        
REVENUE RECOGNITION        
Total revenue 57,838 58,945 99,693 109,075
Product revenue | Sales to enterprise customers        
REVENUE RECOGNITION        
Total revenue 39,335 39,052 60,851 62,284
Product revenue | Sales to service provider customers        
REVENUE RECOGNITION        
Total revenue 56,225 76,005 102,823 134,764
Product revenue | Indirect sales through channel partner program        
REVENUE RECOGNITION        
Total revenue 32,566 38,988 51,895 61,723
Product revenue | Direct sales        
REVENUE RECOGNITION        
Total revenue 62,994 76,069 111,779 135,325
Product revenue | United States        
REVENUE RECOGNITION        
Total revenue 37,011 59,101 57,952 88,442
Product revenue | Europe, Middle East and Africa        
REVENUE RECOGNITION        
Total revenue 24,695 25,534 41,657 44,994
Product revenue | Asia Pacific        
REVENUE RECOGNITION        
Total revenue 30,291 27,966 58,225 59,005
Product revenue | Other        
REVENUE RECOGNITION        
Total revenue 3,563 2,456 5,840 4,607
Service        
REVENUE RECOGNITION        
Total revenue 96,780 105,526 191,272 204,814
Service revenue (maintenance)        
REVENUE RECOGNITION        
Total revenue 66,022 68,297 129,689 134,719
Service revenue (maintenance) | Cloud and Edge        
REVENUE RECOGNITION        
Total revenue 51,878 51,816 102,110 102,584
Service revenue (maintenance) | IP Optical Networks        
REVENUE RECOGNITION        
Total revenue 14,144 16,481 27,579 32,135
Service revenue (maintenance) | United States        
REVENUE RECOGNITION        
Total revenue 34,977 33,546 68,710 66,870
Service revenue (maintenance) | Europe, Middle East and Africa        
REVENUE RECOGNITION        
Total revenue 15,398 18,362 30,081 35,745
Service revenue (maintenance) | Asia Pacific        
REVENUE RECOGNITION        
Total revenue 9,407 9,708 18,637 19,108
Service revenue (maintenance) | Other        
REVENUE RECOGNITION        
Total revenue 6,240 6,681 12,261 12,996
Service revenue (professional services)        
REVENUE RECOGNITION        
Total revenue 30,758 37,229 61,583 70,095
Service revenue (professional services) | Cloud and Edge        
REVENUE RECOGNITION        
Total revenue 20,905 29,120 43,926 54,082
Service revenue (professional services) | IP Optical Networks        
REVENUE RECOGNITION        
Total revenue 9,853 8,109 17,657 16,013
Service revenue (professional services) | United States        
REVENUE RECOGNITION        
Total revenue 17,379 23,575 35,283 43,605
Service revenue (professional services) | Europe, Middle East and Africa        
REVENUE RECOGNITION        
Total revenue 8,999 8,217 16,424 16,873
Service revenue (professional services) | Asia Pacific        
REVENUE RECOGNITION        
Total revenue 2,940 4,078 6,703 6,818
Service revenue (professional services) | Other        
REVENUE RECOGNITION        
Total revenue $ 1,440 $ 1,359 $ 3,173 $ 2,799