Используемые протоколы связи

SIP (Session Initiation Protocol, RFC 3261)
SDP (Session Description Protocol, RFC 4566, RFC 3264 (устаревший))
RTP (Real-time Transport Protocol, RFC 1889, RFC 3550) WIKI
RTCP (Real-Time Transport Control Protocol, RFC 3550) WIKI
STUN (Session Traversal Utilities for NAT) RFC 5389
TURN (Traversal Using Relay NAT, RFC 5766) WIKI
SCTP (Stream Control Transmission Protocol) RFC 4960