H321

H.321 is the ITU standard for video conferencing over B-ISDN and ATM. This ITU standard is from 1995 and deals with the adaptation ofH.320 videophones to the ATM network.

The standard defines video compression(H.262, H.263), audio compression according to G.711 and G.722, multiplexing according to H.221 and multipoint connections(H.231, H.243). Data transmission is in accordance with the T.120 standard, and H.321 specifies the ATM Adaption Layer( AAL) for transport.