The Research Of VoIP Based On P2P

With the extensive utilization of VoIP technology and the rise of the next generation Internet (NGI), IP telephony system based client/server model faces various challenges with the growth of the numbers of its users, especially in scalability. As a decentralized network model, Peer-to-Peer network can make the full use of the resource and capability of every node in the network and provide stronger overall performance and capability, which afford a novel way to resolve the scalability problem of client/server model based IP telephony system.P2P network is dynamic, scalable and self-organized. Therefore, to communicate with other node in the network, the first problem is how to locate the destination node, which is also the key problem in P2P study. This paper presents group based Peer-to-Peer object location algorithm considering the characteristic the VoIP application behaves in the P2P network. The work is divided into the following parts:Several typical P2P routing algorithm were compared with each other and Pastry algorithm as an example of DHT (Distributed Hash Table) search model was analyzed. At the same time, according to the characteristics of VoIP application in the P2P network, we point out the shortages of applying P2P network to VoIP application.The paper designed a group based P2P resource location (GPRL) algorithm, which is efficient, easy-managed and practical. The idea of Bootstrap node is a solution to feasibility problem in P2P routing. A novel routing table structure was proposed to increase the reliability greatly.GPRL algorithm also includes a self-organized random P2P routing algorithm, which describes the course of the update and maintenance of node state when joining and leaving. The election principle of new leader is based on node performance, which improves the resource utilization and system performance.The results of Simulations show GPRL could achieve higher reliability and better query performance. They also show that the update mechanism could recover the performance of the system effectively after nodes failure, which establish solid ground for the realization of a VoIP system based P2P network.