SIP - The Session Initiation Protocol
SIP, the Session Initiation Protocol, is the IETF platform for realtime communication. The SIP specification, RFC 3261, decribes it this way:
This document describes Session Initiation Protocol (SIP), an application-layer control (signaling) protocol for creating, modifying, and terminating sessions with one or more participants. These sessions include Internet telephone calls, multimedia distribution, and multimedia conferences.
The primary application for SIP so far has been Voice over IP or IP Telephony. SIP is however not designed with this as the most important application in mind. It’s a general purpose protocol for locating participants and inviting them to a session of any kind - audio, video, text, gaming, applicationsharing, presentations. Telephony is just one of the applications.
During the years, SIP has attracted more and more interest from the IP Telephony space and has become the primary platform for IP telephony systems. This has lead to a number of extensions to SIP to make it an even better solution for IP telephony while making the implementations less of a general purpose platform. Many SIP networks are not prepared for other applications, like presence, instant messaging, application sharing or gaming.
The amount of documentation on SIP and SIP-related solutions in the IETF is overwhelming. In addition to this, the 3GPP consortium and the PacketCable group has their own set of implementation guidelines for their recommended platforms. Jonathan Rosenberg has produces a good introduction to the IETF documentation in the document named “The Hitch-Hikers guide to SIP“.
This page has the following sub pages.
November 10th 2007
