Study On Streaming Data Delivery Based On P2P And CDN Hybrid Architecture

With the rapid development of the Internet, the media streaming technology has achieved great progress. On the other hand, with the emergence of peer-to-peer (P2P) technology, network bandwidth and the capacity of user end-systems which were ignored in the past become valued computing resources now. How to utilize end-systems resources to build a P2P media delivery system with large-scale, high scalability, reliability and performance in a dynamic peer-to-peer network environment is a hot research topic in recent years.The global present state of the research on the stream delivery technologies are introduced first. Then the three main stream technological frames are explained. Analysis has been performed to pointed out that with current CDN system, when the I/O load is high, the server or the bandwidth will be the bottle neck. And the allocation and maintenance cost of the CDN server is relatively high. Also, the P2P technology has its own problem in stream media delivery. This is because firstly, it requires enough seeds to support the Peer for playing. Secondly, compared to a CDN server, a Peer can only or is willing only to offer a very low uploading bandwidth which might be lower than the required media playback rate. Facing the problems, a Hybrid Three-tie Media Streaming Service Architecture based on CDN and P2P is proposed. The key technology in systematic realizing is discussed according to the system architecture diagram.The core content of this paper includes: reducing Multicast Service Nodes (MSN) joints load on CDN and P2P Video on Demand (VOD). Within the HTMSA, three stages are classified according to the current service capacity theoretical models. Detailed analysis of valid Peer number and system service capacity is carried out for each stage. A cache solving strategy is proposed on large simultaneous clients number to reduce the server load and the delay in playing.All the experiments of this paper were based on Cygwin+NS2 environment. The loading ability and overall service capacity of the HTMSA, the load of Peer cache to the server and the delay at Peer were tested. Results showed a significant improvement in all tested aspects.