8x8 Inc.
AT&T Inc.
Avaya Inc.
Bandwidth Inc. (Bandwidth.com)
IntelePeer Cloud Communications
Lotum Inc.
MessageBird B.V.
Mitel Networks Corporation
Plivo Inc.
Snich AB
Telestax
Twilio Inc.
Vonage Holdings Corp
Voxbone SA
Voximplant (Zingaya Inc.)
Voxvalley Technologies
Wazo Communication Inc.?