Simulation And Implementation Of Bittorrent Locality Based On PDNS

With the development of P2P network, P2P applications occupy most data flow of the Internet. In order to reduce the cross-ISP traffic, some ISPs begin to ban the P2P applications. So, how to reduce cross-ISP traffic becomes an important problem. In this paper, we design and implement the simulation of BitTorrent locality system on the basis of Parallel Distributed Network Simulator (PDNS).In the BitTorrent protocol, there are some different strategies to achieve. For instance, Rarest First, Random First, Choke algorithm and so on. In terms of localization, two algorithms were done. One is based on Tracker, which the tracker will not send peerlist randomly but decided by the IP of the nodes.The other is based on Choking mechanism, which choke the nodes in other ISP, unchoke nodes in the same ISP, and the optimistic unchoking algorithm is kept down.In the simulation, we first take a large-scale test to prove our program is correct. Then analyze the BitTorrent real data,get the user profiles of BitTorrent,which makes our conclusions credible. In the process of testing the performance of each strategy, many metrics and parameters have been used to analyze result of simulation: average downloading time,join time,leave time,and flow between ISPs, etc.The methods and the results presented in this thesis provide important reference to the P2P network file sharing research and application.