SIP Based P2P VOIP System In Corporation Research And Realization

Recently, SIP based Internet phone system in VoIP technology often has a C/S mode. Although this architecture is simple, it has too much limitations. The server in this mode is expensive and hard to maintain or upgrade, and it will obviously become the bottleneck of the system. On the other hand, peer-to-peer (P2P) has become a new growing technology which is the focus of Internet, and brings lots of applications. P2P systems are a kind of distributed system, which is inherently scalable and without centralized server. They inherently have high scalability, robustness and fault tolerance because there is no centralized server and the network self-organizes itself. Therefore, it is very important and practical to take the advantage of both SIP and P2P network to construct a totally new VoIP network architecture.The paper analyses the characteristic of SIP protocol and call flow, researches the processing of SIP message, and some key technology used in P2P core network. Next,analyses the network of Skype and the Chord algorithm,design the network model based on Skype. Further,presents the architecture of our P2P systerm, completes the design of the basic function of P2PSIP platform and the development of the P2P-VoIP soft phone software and operational support system.The paper deals with the problem of traveling Nat using ICE method,researching on solutions of problems about SIP-Based mufti-media communication in the environment of using NAT/FW. This solution can traverse all kinds of NAT/FW without doing any change on the existing equipment. The solution is more alterable than current methods, which is a promising method in application.