The Reliable Algorithm Of Constructing ALM Tree Based On P2P

Multimedia streaming over the Internet is booming nowadays. However, the streaming quality is generally unsatisfactory. For large-scalable broadcasting, the traditional internet model of point-to-point unicast communication dose not scale, the networking research community proposed IP multicast, a network layer service that allows a single source to distribute a data stream to many simultaneous receivers in an efficient manner. However, this network layer approach has met with limited success due to a number of factors including complexity of network protocol itself, its inability to address Internet hetero- geneity, and its lack of support for efficient and scalable transport protocols for reliability and congestion control. As a result, in spite of a decade of existence, the multicast protocol architecture remains just a research commodity with limited penetration into commercially deployed Internet.In order to improve the QoS of streaming over the Internet, Application layer multicast (ALM henceforth) based on P2P network is proposed. The ALM, which need not do any modification on the present network infrastructure, can fulfill the multicast function on the basis of virtual overlay networks. The end-system in the ALM group can undertake the tasks such as duplicating packages, routing and data forwarding. In this way it becomes a convenient and flexible method to deploy multicast services on the Internet.This article first discusses distribution technology of media streaming. Then it analysis ALM based on P2P mode and summarizes features and application modes of ALM. ALM sends packets to group members by the spanning tree, When one or more nodes fail, the downstream nodes cannot receive packets, while makes the system become fragile. Proposed in this paper is a reliable algorithm of constructing ALM tree. Its effectively has been verified through simulation significantly.