The Isp To Assist Research And Simulation Analysis Of The Context Of P2p Vod Application

With the development of internet, VOD service has become a popular application among users as it allows them to watch the video while downloading. The traditional VOD system is of C/S structure and the quality of service will be affected with increasing users. Currently there exist two approaches to this problem:(1) Adopt P2P to utilize the available bandwidth of users to decrease the load on servers; (2) Deploy CDN server cluster to provide more powerful service. Shanghai Telecom applies the latter solution for its IPTV VOD system. However, both solutions have their advantages and disadvantages. For P2P, intrinsic scalability is a preferable merit. But it could hardly provide stable service due to the heterogeneity in different network and peer's dynamic churn. Besides, it incurs extra cross-traffic to ISP because of mismatch between the overlay and the underlay network topology. For CDN, it could provide reliable service with its surrogate servers which are placed efficiently according to underlay topology. However, with increasing users, CDN becomes very costly as more servers are deployed. Thus, problem rises as how to combine these two solutions to provide better VOD service and for Shanghai Telecom case, how to add P2P mechanism into CDN and evaluate its performance before deployment.We propose an ISP-Friendly P2P-CDN hybrid VOD scheme base on the characteristic of IPTV VOD system. Take into account of the complexity of network behavior, we design and implement a scalable P2P simulator for IPTV to achieve efficient evaluation. This simulator can be used in future research with its good modality and scalability. In this paper, we implemented the P2P-CDN hybrid architecture based on our simulator. Then we evaluate the performance under different network status and user behavior configurations according to the requirement of Shanghai Telecom. The result indicates that P2P's performance is limited by current network condition. Its performance can be efficiently improved if we can upgrade the network or attract more available idle users to upload. Meanwhile, we analyze the impact of various user behaviors on P2P performance in detail.