Architecture of multiparty conferencing using SIP

Multiparty conference is an important telephone service. However, today, the session initiation protocol (SIP) is primary used in point-to-point calls. SIP can support multi-party conferencing in many different ways. This article introduces some SIP conferencing architectures, their advantages, disadvantages and performance. According to centralized conferencing model, we construct feasible system architecture, which can support middle scale conference. After that we analysis the key technologies in centralized SIP conference, like media server design and audio mixing. At the end of this paper, the system's performance is evaluated and discussed.