Technology Of Streaming Media Based On P2P Networks

Real-time streaming media system based on P2P technology includes the following two aspects of research: the first is the transmission scheduling strategy of data blocks, that is media content is divided into the same size of pieces, and how to requests the data block;the second is the construction of overlay network, this process is known as members of the management, that is constructed overlay network is closer to the underlying network topology, the more it can improve the overall transmission performance, Because the overlay network topology matching with the underlying data transfer path can reduce data transmission dalay and cross-ISP traffic.This paper studies these two issues, the main contributions are as follows:1:Data scheduling algorithm is point to a user how to obtain the required sequence of data blocks, and from which node to obtain the data block. Existing data scheduling algorithm is prior to access less data blocks, so that the share properties of fresh data would be ignored for a long time.because fresh data sent from the server with the larger ID and these fresh data is on the location of the buffer,this data has enough time to stay in the buffer and it can be requested by another node. Based on these, this paper presents gragh coloring based data scheduling algorithm GCB(Graph color-based algorithm ), in this algorithm, the obtaining data nodes not only follow the principle of uniform distribution but also take the duration of the sharing sliding window into account, sharing data in the sliding window for a longer time will enjoy a certain priority level.This strategy is more effective especially when sbandwidth resources are scare and number of connections is limited.2: Taking into account the mesh-based network is effective against node dynamic, but the structures do not take into account the problem of proximity between nodes, thus increasing the amount of internet traffic and transmission load, compared to the mesh-based network, tree-based network considers the proximity problems of network, thus this structure produces less internet traffic.This paper conbines advantages of mesh-based network and tree-based network, and proposes combination of the tree and mesh–based strategy TMPS(Tree and Mesh Peer Selection) , In the TMPS, each node is both belongs to the tree topology and mesh topology, tree and mesh topologies selecte neighbers and distribute data together. Tree-based protocol is responsible for solving proximity problems and be facilitate to find parent node for new nodes. Mesh-based protocol is responsible for the mangement of each node. The combination of tree-based protocol and mesh-based protocol can make full use of advantages of two protocols, and avoid the shortcomings of their own, making the transmission of streaming media obtain better data transmission performance and goog scalability.