H.323 is the international standard for multimedia communication over packet-switched networks, including LANs, WANs, and the Internet. It was first defined by the ITU in 1996 and has been updated regularly. The most recent version is H.323 version 7 (2009).
H.323 is an "umbrella" specification, which includes the standards H.323, H.225.0, H.245, the H.450-series documents, and the H.460-series. It allows for the use offor data collaboration and file transfer. When referring to the system and set of documents, people generally refer to "H.323", though not every document is mandatory as part of a standard H.323 system. For example, H.460.2, which describes number portability, is generally not used in enterprise systems.
The scope of H.323 covers real-time voice, video, and data communication over packet-switched networks. It was designd from the outset to operate overnetworks, primarily, though H.323 may also operate over other packet-switched networks. It was designed with multipoint voice and video conferencing capabilities, though most users do not take advantage of the multipoint capabilities specified in the protocol.
H.323 was the world market leader for transporting voice and videoand video networks around the world, with literally billions of minutes of voice traffic every month alone.