Patent ID: 8060640

Claim:
A method in a computer system for reducing network traffic that uses a session initiation protocol (â€œSIPâ€) to provide presence information, the method comprising: receiving at a server SIP requests from clients, the received SIP requests requesting to subscribe to presence information provided by the server; and for each received SIP request received from one of the clients, creating a SIP response to the received SIP request from the client, the created SIP response indicating that client has been successfully subscribed to presence information provided by the server; creating a SIP notify request that includes presence information provided by the server; determining whether the received SIP request from the client includes an indication that the client supports combining SIP requests with SIP responses and whether the server supports combining SIP requests with SIP responses; upon determining that not both the client and the server support combining SIP requests with SIP responses, sending to the client the created SIP response; sending to the client separately from the created SIP response the created SIP notify request wherein the client sends a SIP notify response to the SIP notify request when the SIP notify request is sent separately from the created SIP response; and when a SIP notify response to the sent SIP notify request is not received from the client within a certain time period, sending to the client another SIP notify request that includes presence information provided by the server; and upon determining that both the client and the server support combining SIP requests with SIP responses, adding to the created SIP response the created SIP notify request and an indication that the server supports combining SIP notify requests with SIP responses; sending to the client the created SIP response including the added SIP notify request from the server wherein the client does not send a SIP notify response to the SIP notify request added to the SIP response; and when the client does not receive the sent SIP response including the added SIP notify request, receiving at the server the SIP request that is resent from the client so that when both the client and the server support combining SIP requests, a separate SIP request notifying the client of initial presence information to which the client has subscribed is avoided.