v3.26.1
REVENUE RECOGNITION (Tables)
6 Months Ended
Jun. 30, 2026
REVENUE RECOGNITION  
Schedule of timing of performance obligation

  ​ ​ ​

When Performance Obligation is Typically 

  ​ ​ ​

Performance Obligation

Satisfied

When Payment is Typically Due

Software and Product Revenue

Software licenses (perpetual or term)

 

For perpetual licenses, typically when made available for download (point in time); for term-based licenses, at the beginning of the specified term (point in time)

 

Generally, within 30-60 days of invoicing, except for term licenses which may be paid for over time

Software licenses (subscription)

 

Upon activation of hosted site (over time)

Generally, within 30-60 days of invoicing

Hardware

 

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

 

Generally, within 30-60 days of invoicing

Software upgrades

 

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

 

Generally, within 30-60 days of invoicing

Customer Support Revenue

 

  ​

 

  ​

Customer support

 

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

 

Generally, within 30-60 days of invoicing

Professional Services

 

  ​

 

  ​

Other professional services (excluding training services)

 

As work is performed (over time), typically on the input method based on hours incurred

 

Generally, within 30-60 days of invoicing (upon completion of services)

Training

 

As the training is delivered (over time), typically one to five days

 

Generally, within 30-60 days of services being performed

Schedule of disaggregation of revenue

  ​ ​ ​

  ​ ​ ​

Service revenue

  ​ ​ ​

Product

Service revenue

(professional

Three months ended June 30, 2026

revenue

(maintenance)

services)

Total revenue

United States

$

37,011

$

34,977

$

17,379

$

89,367

Europe, Middle East and Africa

24,695

15,398

8,999

49,092

Asia Pacific

30,291

9,407

2,940

42,638

Other

3,563

6,240

1,440

11,243

$

95,560

$

66,022

$

30,758

$

192,340

  ​ ​ ​

  ​ ​ ​

Service revenue

  ​ ​ ​

Product

Service revenue

(professional

Three months ended June 30, 2025

revenue

(maintenance)

services)

Total revenue

United States

$

59,101

$

33,546

$

23,575

$

116,222

Europe, Middle East and Africa

 

25,534

 

18,362

 

8,217

 

52,113

Asia Pacific

 

27,966

 

9,708

 

4,078

 

41,752

Other

 

2,456

 

6,681

 

1,359

 

10,496

$

115,057

$

68,297

$

37,229

$

220,583

  ​ ​ ​

  ​ ​ ​

Service revenue

  ​ ​ ​

Product

Service revenue

(professional

Six months ended June 30, 2026

revenue

(maintenance)

services)

Total revenue

United States

$

57,952

$

68,710

$

35,283

$

161,945

Europe, Middle East and Africa

 

41,657

30,081

16,424

 

88,162

Asia Pacific

 

58,225

18,637

6,703

 

83,565

Other

 

5,840

12,261

3,173

 

21,274

$

163,674

$

129,689

$

61,583

$

354,946

  ​ ​ ​

  ​ ​ ​

Service revenue

  ​ ​ ​

Product

Service revenue

(professional

Six months ended June 30, 2025

revenue

(maintenance)

services)

Total revenue

United States

$

88,442

$

66,870

$

43,605

$

198,917

Europe, Middle East and Africa

 

44,994

 

35,745

 

16,873

 

97,612

Asia Pacific

 

59,005

 

19,108

 

6,818

 

84,931

Other

 

4,607

 

12,996

 

2,799

 

20,402

$

197,048

$

134,719

$

70,095

$

401,862

The Company’s product revenue from its direct sales program and from indirect sales through its channel partner program for the three and six months ended June 30, 2026 and 2025 was as follows (in thousands):

Three months ended

Six months ended

June 30, 

June 30, 

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

Indirect sales through channel partner program

$

32,566

$

38,988

$

51,895

$

61,723

Direct sales

 

62,994

 

76,069

 

111,779

 

135,325

$

95,560

$

115,057

$

163,674

$

197,048

The Company’s product revenue from sales to enterprise customers and from sales to service provider customers for the three and six months ended June 30, 2026 and 2025 was as follows (in thousands):

  ​ ​ ​

Three months ended

Six months ended

June 30, 

June 30, 

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

Sales to enterprise customers

$

39,335

$

39,052

$

60,851

$

62,284

Sales to service provider customers

 

56,225

 

76,005

 

102,823

 

134,764

$

95,560

$

115,057

$

163,674

$

197,048

The Company’s product revenue and service revenue components by segment for the three and six months ended June 30, 2026 and 2025 were as follows (in thousands):

Three months ended

Six months ended

June 30, 

June 30, 

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

Product revenue:

Cloud and Edge

 

$

37,722

 

$

56,112

 

$

63,981

 

$

87,973

IP Optical Networks

 

57,838

 

58,945

 

99,693

 

109,075

Total product revenue

 

$

95,560

 

$

115,057

 

$

163,674

 

$

197,048

Service revenue:

 

  ​

 

  ​

 

  ​

 

  ​

Maintenance:

 

  ​

 

  ​

 

  ​

 

  ​

Cloud and Edge

 

$

51,878

 

$

51,816

 

$

102,110

 

$

102,584

IP Optical Networks

 

14,144

 

16,481

 

27,579

 

32,135

Total maintenance revenue

 

66,022

 

68,297

 

129,689

 

134,719

Professional services:

 

  ​

 

  ​

 

  ​

 

  ​

Cloud and Edge

 

20,905

 

29,120

 

43,926

 

54,082

IP Optical Networks

 

9,853

 

8,109

 

17,657

 

16,013

Total professional services revenue

 

30,758

 

37,229

 

61,583

 

70,095

Total service revenue

 

$

96,780

 

$

105,526

 

$

191,272

 

$

204,814

Schedule of customer assets and liabilities

The changes in the Company’s accounts receivable, unbilled receivables and deferred revenue balances for the six months ended June 30, 2026 were as follows (in thousands):

Unbilled

Deferred

Deferred

Accounts

accounts

revenue

revenue

receivable

  ​ ​ ​

receivable

  ​ ​ ​

(current)

  ​ ​ ​

(long-term)

Balance at January 1, 2026

$

161,007

$

70,878

$

124,425

$

31,654

Increase (decrease), net

 

(17,660)

 

5,978

 

(6,092)

 

2,978

Balance at June 30, 2026

$

143,347

$

76,856

$

118,333

$

34,632