1. 8X8 Inc.
2. Ascom Holding AG
3. AT&T Inc.
4. Avaya Holdings Corp.
5. CallHippo
6. Cisco Systems Inc.
7. Citrix System Inc.
8. Deutsche Telekom AG
9. DIALPAD Inc.
10. GoToConnect
11. Ignite Solutions Group
12. Intermedia.net Inc.
13. Microsoft Corporation
14. Mitel Networks Corp.
15. Nextiva Inc.
16. Ooma
Inc
17. OpenPhone Technologies Inc.
18. Orange S.A.
19. Pulse Telesystems Private Limited
20. Ribbon Communications Inc.
21. RingCentral Inc.
22. Tata Communications Limited
23. Telecom Italia Sparkle S.p.A
24. Verizon Communications Inc.
25. Zoom Video Communications Inc.