Key Technology In Research And Application Of P2P NetWork

With the popularization and development of the Internet, the Internet has been closely related to people's lives. As the number of people accessing to the Internet grew rapidly, it brought many new challenges to the traditional client / server network model. In order to adapt to this changing in Internet and better satisfy the increasing demand, Peer-to-Peer (referred as P2P) technology has been rapidly developed and has drawn much attention as one of the most popular topics in industry and research community in recent years. However, P2P technology has just begun, so far, there is no uniform standard to follow, it is in the developing and optimizing stage. P2P technology canceled the architecture of central-server and all nodes which have the same status constitute a self-organizing system automatically. Therefore, the biggest challenge in P2P system is how to find and locate the data under the condition of the absence of central-server. In this research area,there have been several excellent algorithms, but at the same time, there also have some problems.In this dissertation, to solve the shortcomings of the Chord which is widely used in P2P systems, a new model of Chord is provided in which the original Chord ring is divided into two parts, inter Chord and intra Chord. Each node decides which ring to join by broadcast, the intra Chord or the inter Chord, The physically adjacent nodes are organized in one intra Chord to enhance the system's speed of query. In the intra Chord, each node only needs to know its direct predecessor and direct successor and leader node, and nodes' joining in or out of the intra Chord will not affect the whole system, it also can increase the stability of the system. The new algorithm of Chord is verified through MIT's open source simulation tool called P2Psim. The experimental results show that the new Chord model not only overcome the shortcomings of the original Chord model, but also retains the original model Chord's merits, thus optimize the overall performance. In addition, the open-source P2P technology JXTA's routing algorithm is also researched in this dissatation. JXTA technology can be applied to develop a series of P2P applications. But its stability and reliability are low because JXTA uses broadcasting in its routing algorithm which may cause a great deal of information redundancy, the sharp increasing in network traffic, uncertainty of the query. The new model of the Chord algorithm can greatly reduce the network of redundant information and deal with queries in limited times, and have great similarity with JXTA routing model. So it can put the new model of the Chord routing algorithm to the JXTA routing algorithm to improve the efficiency, finaly, With JXTA, a real-time communication system is designed.