The Research And Design Of Internet Phone Based On P2PSIP

With the constant development of IP technique and the appearance of VOIP in recent years, the data network communication has involved traditional voice business. Due to the large market potential and expansive development future of the mergence of traditional voice business and data business, the development of VOIP technique will also has a large development space and development potential. 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) systems are a kind of distributed system, which is inherently scalable and without centralized server. They have no such problems as bottleneck or server maintenance, and 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 article mainly makes a research on the new network system------P2PSIP Internet Phonebased on P2P network architecture and SIP standard. It takes advantages of both P2P system and SIP standard and points out a new direction for VOIP development. In the article, we make a deep research on its related techniques, then design and realize the solution of P2PSIP-based Internet phone system. The related techniques include source management in P2P network, the definition and implementation of SIP standard, and the NAT traversing, etc.The article firstly analyzes the source management in P2PSIP network model, where the main source is the network nodes. We take Chord arithmetic to manage and maintain all the nodes in P2PSIP system. We classify all the P2PSIP network nodes into two classes according to their performance: Super node and Ordinary node. An ordinary node is just a SIP end point, and its route information is saved to certain super node through Chord arithmetic. The super nodes form Chord ring. A super node is more than a SIP end point. It is in charge of the node's finding, the node's registering, the node's leaving and so on. We described the technique of node's start-up, node's registering and node's failure in detail with Chord arithmetic in this article.