Power Rate And The Small-world Characteristics Of P2p Overlay Network Design And Analysis

Peer-to-Peer(P2P) network technology currently is a hotspot in the computer network research field.The main purpose is to fully utilize the potential resources of Internet,which includes computing resources,storage resources and file resources,etc.The P2P overlay network applies equality policy in which peers simultaneously function as both "clients" and "servers".Due to its low cost,high scalability,fault-tolerance,autonomy and self-organizing nature,P2P overlay network is becoming an ideal platform for information sharing.The study of P2P overlay topology is always an important component in the research of P2P overlay network,which directly affects the application and further development of P2P technology.Our work focuses on the P2P overlay network,the power-law relationship and the small-world property.The system is commonly known as a power-law network since the degree distribution is not a function of the number of peers,but follows a power-law distribution.This phenomenon has been represented by the probability of peers with K degrees as P(k)～k^-r, where 1＜γ＜∞.In the second chapter we design a resilient and cooperative P2P overlay based on power-law relationship REPL,analysis high performance as Well as resilience to attacks of malicious users.In addition,we study the free-riding problems of the selfish peers.We generate a utility function to measure the peers' contributions to the network.The peers discover other peers randomly from the entire network,compare performance against those peers and rewire. In the simulation,we demonstrate that the rewiring procedure increases the cooperation of peers in the REPL.Preferential Attachment rule is widely used to construct the unstructured P2P overlay network based on power-law relationship.These networks have low tolerance to attacks targeted to "hub" peers.It has been also reported that the attack strategy based on betweenness centrality much harms network connectivity.In the third chapter we modify the preferential attachment rule,design the unstructured P2P overlay network model HLD and HHD,show that these two models are better than preferential attachment model in robustness and load-intensity.Due to the uncooperative nature of peers in the unstructured P2P overlay network based on power-law relationship,peers typically do not want to take the burden of storing excessive amount of control information for others in the network.To achieve fairness and practicality among all peers,we limit the number of neighbors to a predefined value,explore the local topology information for generating an unstructured P2P overlay network LPA,and investigate the better effect of limited degree on the search in the fourth chapter.The network with small-world property can be characterized by small average path length and large cluster coefficient.In the fifth chapter,we propose a content cluster P2P overlay network based on small-world property,namely CCSW.In the CCSW,peers with similar contents organize into peer clusters.In the experiment evaluation,we demonstrate that with the constant number of links and the small average path length,the CCSW overlay network has low maintenance cost and high search performance.