Asynchronous Service State Notifications From SIP Entities
This document describes the requirement for in-advance asynchronous service state notifications from a SIP[1] entity to its USER.The notifications MAY be about the state of the entity or the state of the session. It also explains certain mechanisms for implementing the same. This document is divided into three parts. 1)An Event Specification. 2)Use cases for event specification and mechanisms to extend this specification. 3)Limitations and Future work.