Similar to MGCP

OSIP

Skype

Tango (software)

TeamSpeak

Telecoms & Internet converged Services & Protocols for Advanced Networks

Tox (protocol)

Wide-coverage Internet Repeater Enhancement System

Asterisk (PBX)

Ekiga

Empathy (software)

KakaoTalk

Google Hangouts

Google Voice

Zoom (software)

Softphone

Discord

Viber

Line (software)

Line Music

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