Method and apparatus for a SIP client manager

A method, apparatus, system, and computer program product for communicating using Session Initiation Protocol (SIP) is provided. The method, apparatus, system and computer program product provide mechanisms by which simplified messages may be utilized by client applications such that the client applications need not maintain information pertaining to the routing of messages. The system includes a network interface and a SIP client manager that receives SIP messages through the network interface. The SIP client manager contains a SIP management module and an X-SIP client module. The SIP management module contains a SIP message modifier for modifying incoming messages and outgoing messages in accordance with context information or state information for a session associated with a SIP message, and the SIP management module also contains input/output controllers for receiving, sending, or forwarding SIP messages. The X-SIP client module contains an input/output controller for receiving and sending SIP messages and also contains a SIP application programming interface (API) for handling SIP messages for a SIP-enabled application.