Research On Routing Protocol Of P2P Network System

P2P technology also calls peer to peer technology, a new idea of network structure. The basic difference between P2P and client/server structure is no center node in network. In P2P system, any node has equal degree and has three functions: information consumer, information provider, and communication.Recently, P2P technology becomes a newly hot topic, it provides great freedom and advantage, it tries to coordinate internet latent resources, and it turns static HTML pages internet into dynamic access by free mutual internet with great capacity of information. P2P has drawn more and more people's attention for its great technology potential. It is wildly used in file sharing, distributed computing, collaboration, instant message, etc.Because of free connection in earlier P2P system, data query must rely on flooding. Large amount of resource network was wasted. So, a structured overlay network was advanced, and distributed hash table technology(DHT) based on structured overlay network turns a focus topic in P2P research. Essential problem in DHT is routing algorithm. However, the quality of route algorithm has directly related to performance and expansibility of P2P system.This thesis first researches the structure of P2P system, and analyzes the hot problem: structured overlay network and routing algorithm with distributed hash table(DHT). Then the thesis gives a normal analysis of routing algorithm from architectures, routing arithmetic, node join and exit, routing table size, average pathway length, such as Chord, CAN, Pastry, Tapestry, kademlia. The thesis compares these protocols by analyzing state-efficiency compromise, tolerance, hot information and node heterogeneity. With the help of software Emule and all above analysis, a self-adapting routing algorithm Kad_BOA. is proposed. Compared with previous algorithms, it has several advantages: avoiding overlarge routing table, making the most use of bandwidth, dynamically adjusting its run level with churn of network, joining this P2P system timely without any requirement, little press on neighbor nodes, excellent expansibility and communication.Finally, an application framework of streaming media based on improved Kad_BOA algorithm PCDN is presented. Main parts of this PCDN system are listed. And experimental results are analyzed which shows that the advanced algorithm reduces effectively the maintenance overhead and improves greatly the availability of P2P resource.