Session Initiation Protocol (SIP)
This protocol handles the signalling used in VoIP applications. Signalling traditionally this takes care of how calls are set up and torn down. This has four major responsibilities.
- User location - the parties finding one another,
- Session establishment - handling the callee accepting, rejecting or redirecting the call,
- Session negotiation - endpoint synchronizing on the same standard,
- Call participation management - handling people joining or leaving.p