Reseach On P2P Overlay Network Topology Optimization

Currently peer-to-peer (Abbreviated as P2P) application has developed to be one of the most important applications on Internet. P2P overlay network is a carrier of various types of P2P application, the topological propertiy of P2P overlay network is one of the most important factors influencing the OoS of P2P application. However, with the development of P2P technology, free-riding in P2P network is growing to be a more and more serious problem because of large scale system and strong dynamicity, it has brought a negative impact on network robustness, availability and life cycle. Optimizing overlay topology and inhibiting effectively free-riding are important topics in the current P2P network reseach.In order to overcome the problems such as the free-riding behavior widely existed in P2P overlay network and being vulnerable for P2P systems,we study the topology optimization in depth.The main work of this paper is as follows: This paper analyzes and compares the different topologies and characteristics of P2P overlay network, and does some reseach on the super-node function of the hybrid P2P overlay network, trust mechanism, incentive mechanism.A super-node selection mechanism based on indirect reciprocity between nodes is introduced in order to overcome the existing unreasonable super-node selection and to inhibit free-riding behavior. According to this new mechanism, super-node can be selected and free-riding node can be identified by the node reputation value.A group domain division method based on link weight is introduced in order to solve the topological inconsistencies in P2P overlay network. Nodes closer to each other in physical position are allocated to one group domain in this method.A Strategy with three center is introduced in order to solve the traditional single-point failure. And a hybrid P2P overlay network is constructed. Some simulation experiments are made to test the topology characteristics and search performance of the new P2P overlay network. The experiment gives the better performance for the new P2P overlay network.