H.323

H.323 is the VoIP protocol defined by Ecma International (European association for standardizing information and communication systems). Like SIP H.323 defines the control part of the call and it uses RTP for the voice part of the call. Unfortunately, H.323 is based on a traditional telephone system and tried to be all things to all people – it turned out to be too complicated for the Internet community and, although popular in the late nineties seems to be dying out in VoIP usage today.

For more information on H.323 use the following links:

• OpenH323 – Open Source implementation project (this has lots of H.323 information).