A Hybrid Application Layer Multicast Model Based On Virtual P2SP

To improve the efficiency of data distribution in large scale ALM with single source, in addition to reduce the transmission delay, A Hybrid Application Layer Multicast Model Based on Virtual Peer to Server and Peer (VPHM) is presented. And the achievements are as following:(1) The nodes in virtual server layer are divided into two types, and one type of nodes is responsible for data distribution while the others are used for node control. The virtual server layer can improve the robustness and provide service to lower layer nodes.(2) Based on multi-layer, non-centralized Peer to Peer (P2P) technology is introduced into lower layer of VPHM. It reduces the load of application server and dependency of Content Delivery Network (CDN), restricts the scope of using P2P, and makes the best of the network resource.(3) Nodes can dynamically float between different layers according to priority algorithm. It provides a manner to adapt to changing network environment by timely adjusting the node's role. Finally, relational conclusions are well proved by network simulation. The result reveals that: those technologies could reduce average end to end delay, improve data distribution efficiency, and the mode suits large scale ALM with high quality of service.