Basic call flow for interoperability test in the presence services based on SIP

Presence service is emerged to meet the needs of integrated service and presence service will be a core function within integrated service. IETF SIMPLE WG generates standard SIP extensions for presence service. In this paper, we described the presence service systems including internal logical function modules. We classified functions of presence service systems with itemized functions, conditions to be occurred related SIP request messages and response message for each request message. And, we also described the basic call flows for interoperability test among presence service systems based on SIP.