SIP (RFC 3261~3266 and various SIP draft extensions), SDP(RFC2327), RTP/RTCP(RFC 1889, 1890) G.711μ-law, G711a-law, G.729, G.729a/b Web browser, Touch-tone telephone keypad configuration with voice prompt, Auto-provisioning system (option), StrongVoIP IntelliManage?Reverse Control even residing after NAT/Firewall, Periodic 揌eartBeat?Monitor