ITU standards used for Videoconferencing

H.320	*Narrow-band visual telephone systems and terminal equipment*
H.323	*Packet-based multimedia communications systems*
H.261	*Video codec for audiovisual services at p x 64 kbit/s*
H.263	*Video coding for low bit rate communication*
*H.264*	*Advanced video coding for generic audiovisual services*
H.221	*Frame structure for a 64 to 1920 kbit/s channel in audiovisual teleservices*
H.242	*System for establishing communication between audiovisual terminals using digital channels up to 2 Mbit/s*
H.230	*Frame-synchronous control and indication signals for audiovisual systems*
G.711	*Pulse code modulation (PCM) of voice frequencies*
G.722	*7 kHz audio-coding within 64 kbit/s*
G.728	*Coding of speech at 16 kbit/s using low-delay code excited linear prediction*
H.243	Procedures for establishing communication between three or more audiovisual terminals using digital channels up to 1920 kbit/s
H.281	*A far end camera control protocol for videoconferences using H.224*
T.12x	Data protocols for multimedia conferencing