Research And Design Of SIP-Based P2P IP Telephony System

VoIP is one of the most important applications in the Next Generation Network. SIP(Session Initiation Protocol) is one of the signaling protocols to develop the VoIP system. SIP is simple, flexible, distributed controled and easy to be extended. And 3GPP has adopted SIP as the controlling protocol for the IP Multimedia Subsystem. All of this makes research of SIP be a spotlight in the field of IP telephony's research.At present, most of the IP telephony systems which is based on the SIP are Client/Server model. The C/S model has a serious problem—server's bottleneck. And it is difficult to deploy the system rapidly in a small environment. The thesis brings on the Peer-to-Peer IP telephony modle. There is none of servers in the P2P model. It is a distributed control system. Every node in the system, which has the same function, is not only a client but also a server. So there is no bottlenect problem. And it's easy to deploy the P2P system.The thesis focuses on a new SIP-based Peer-to-Peer IP telephony. It analyses and researches the SIP protocol and Chord algorithm. Then it extends the SIP protocol in order to support the P2P. And it makes a research on the node register, resource location in detail. Upon these researchs, a model of a SIP-based P2P IP telephony system has been designed.