1. 3CX
2. 8x8 Inc.
3. AT&T Intellectual Property
4. Atlantech Online Inc.
5. AVOXI
6. BullsEye Telecom
7. Cisco Systems Inc.
8. Mitel Networks Corporation
9. NEC Corporation
10. Nextiva
11. NovoLink Communications Inc.
12. RingCentral Inc.
13. Star2Star Communications
14. TPx Communications
15. Verizon Communications Inc.