1. Cisco Systems Inc
2. Five9 Inc
3. Genesys Telecommunications Laboratories Inc
4. Avaya Inc
5. 8X8 Inc
6. Amazon Web Services Inc
7. Enghouse Interactive Inc
8. Unify Inc
9. Sap Se
10. Nec
11. Aspect Software
12. Atos
13. Vonage
14. Zte Corporation
15. Nice
16. Lifesize
17. Talkdesk
18. Vocalcom