The Design And Realization Of NS2-based PeerCast Simulation Platform

In recent years, streaming media applies a lot on Internet. But the traditional C/S pattern's excessive reliance on performance of media server and bandwidth makes quality of streaming media not satisfactory. To solve this problem, P2P technology has been introduced to the streaming media applications. P2P streaming media technology is robust, scalable, bandwidth adaptable, and many other advantages. But since the number of nodes in P2P networks is large, the number of users online at the same time is also large, which make the network features hard to be detected and understood, go against to protocal analysis and improvement. Therefore, simulating the P2P streaming media protocal has been an important manner to study on it.This thesis simulated PeerCast, a classical software of P2P streaming media, on the network simulating platform: NS2. It is a P2P streaming media model based on tree strcture.First, analyzed in-depth the system infrastructure, work processes, mainly algrithm, and its self-regulating PCP communicating protocal, understood the operation mechanism.Secondly, in order to reduce the complexity of PeerCast software to access to NS2, this thesis designed and implemented a network communicating interface platform-NCIP, which was based on NS2. This Application platform can provide the interface to facilitate the accession of NS2 simulation, and the platform has a broad-based. It provides convience for researchers who are not familiar with NS2, can help to speed up the network application software research and extension.At last, transplanted PeerCast to NS2 and simulated the software large-scaled running, analyzed and explore the data gained from experiments, found out the inadequacies PeerCast software. Finally, improved the algrithm of PeerCast nodes' join in, withdraw, finding ChanHits and etc. Aim at tree balancing problem, and simulated the improved algrithm for observation. Simulating and improving PeerCast can help to grasp the runtime network situation of P2P streaming media software, was of great significance for development and research of P2P streaming media software.