A distributed multimedia conferencing based on SIP

Technology of multimedia communications on network is rapidly developing today. SIP (Session Initiation Protocol), which plays an important role in 3G standards, is well applied in multimedia conferencing systems. Traditionally, most SIP-based conferencing systems have been limited in scalability due to their tightly coupled centralized structures. However, distributed conferencing based on SIP is still in the theory phase. The goal of this paper is to take out a practicable solution that can meet the requirement of large scale multi-party communications. We analyze the drawbacks of existing conferencing models, and design a more practical distributed architecture for a large scale conferencing service. For high scalability, coordinated processors are settled in different areas to maintain conferences, and associated mixers are located for media treatment. There are some high speed corresponding channels among processors in different networks for communication and synchronization. We also propose a backup system to keep up meetings when an abrupt breakdown occurs on some server.