Research On VOD Multicast Algorithm Based On P2P Model

With the development of multimedia and network technology, application and research of stream media which is a cross-subject have made considerable progress. Because the large data of multimedia and higher demands of the network bandwidth, the conventional multicast is difficult to meet the requirements. Application level multicast (ALM) implements multicast in application layer, thereby it is convenient to use ALM by only installing software rather than adjusting the physical frame of the network. So that P2P stream media based on ALM has greatly improved. Based on P2P technology, the dissertation studies multicast tree algorithm of Video on Demand (VOD), which can lay out nodes on the multicast network in the network in order to complete the multicast task quickly through considering the network node communication capability and the communication weights between nodes.First, based on the multi-link concurrent multicast tree model, the dissertation proposes the weight first (WFI), the joint first (JFI) and the factors integrated (FIN) multicast tree algorithm respectively after analysis of P2P communication technology, application layer multicast and P2P multicast algorithm. According to media network environment, combined with the structural characteristics of P2P network which has tree manager node (TMN). Then it introduces the maintenance plan of multicast tree to solve the communication efficiency problem of the nodes join and leave the multicast tree. Compared among the branch first (BFI), JFI, WFI and FIN algorithm, the results show that FIN algorithm has better multicast effect in the range of various weights. Finally, the dissertation develops a test software to analyze P2P multicast algorithm, to facilitate the further study of multicast tree algorithm of VOD which based on P2P.