From Fedora Project Wiki
Unified Communications and Real-Time Communications (RTC) concern the integration of multiple communication modes, including email, chat, voice and video, using common identifiers (usually the email address) and multiple protocols (include SIP, XMPP, IRC and WebRTC)
For further details, see:
- the VoIP packages in Fedora
- the Federated RTC objective delivered in Fedora 19