FaceTime is based on numerous technologies: * H.264 and AAC – video and audio codecs respectively * SIP – IETF signaling protocol for VoIP * STUN,

FaceTime is based on numerous technologies: * H.264 and AAC – video and audio codecs respectively * SIP – IETF signaling protocol for VoIP * STUN, TURN and ICE – IETF technologies for traversing firewalls and NAT * RTP and SRTP – IETF standards for delivering real-time and encrypted media streams for VoIP http://en.wikipedia.org/wiki/Facetime http://en.wikipedia.org/wiki/Facetime Sounds very similar to iChat videoconferencing, which also uses h.264, AAC, SIP, RTP and SRTP. The only difference I could find is in the way iChat traverses firewalls and NAT, which it does via SNATMAP. http://support.apple.com/kb/HT1507 http://support.apple.com/kb/HT1507