Conferencing Standards

The International Telecommunications Union (ITU) standards body maintains these four important specification families for conferencing technologies:

ITU H.320 was adopted in 1990 and refers to a suite of specifications setting standards for multipoint audio/videoconferencing over digital switched networks. H.320 sets standards for conferencing over ISDN links only, laying a foundation for room-based confere nce systems that will be most useful to organizations tha t can afford the high-priced facilities. ITU T.120 is part of this suite.

ITU T.120 specifies protocols for use by multipoint document conferencing and data-sharing applications, and it includes functions such as image sharing and exchange, electronic whiteboard conferencing, and file transfer. Some of these protocols, most importantly those defining how conferencing applications interact and what they do, have already been ratified. Other protocols in the suite, in particular those defining conferencing control and reservations services, have not yet been finalized.

The ITU H.323 standard suite addresses multipoint audiovisual communications. As an extension of H.320, it specifies services over ISDN and plain old telephone service (POTS) direct links as well as over IP internetworks and Ethernet LANs.

The ITU H.324 standard suite addresses sharing audio, video, and data using point-to-point analog modem connections over POTS; this specification is analogous to the H.320 su ite for conferencing over ISDN and switched data circuits.

A good source of information about ITU standards is at http://www.itu.ch , the ITU site. For information about interoperability among products supporting these standards, check out http://www.imtc.org , the International Multimedia Teleconferencing Consortium Web site.