Application layer multipoint conference using SIP

The Session Initiation Protocol (SIP) provides advanced signaling and control functionality for a wide variety of multimedia services. This paper introduces an extension of Session Initiation Protocol (SIP) to support multipoint conference. Via functions, a multipoint conference could be constructed by mobile hosts (User Agents, UAs). It requires no server side or network structure modifications. Considering the network performance and end-to-end delay, we propose a new multipoint mobile multicast location management mechanism using SIP. In this mechanism, each data packet is sent out using multicast and routed in a shortest path between any two members of a conference. This paper also introduces the analytical model and performs simulation experiments using Network Simulator 2 (NS2). The experiment results demonstrate that this extension of SIP carries advantages in end-to-end packet delay and the processing time for a new participant to join a multipoint conference.