A scalable peer-to-peer video-on-demand system with asynchronous transfer

Providing Video-on-Demand (VoD) service over the Internet remains to be challenging due to the diversity of client requests and the requirement of high bandwidth. Based on the requirements of high-quality video application, in this paper, we present an unstructured Peer-to-Peer (P2P) VoD system with asynchronous data transfer among peers and centralized directory service. Some new algorithms for choosing supplying peers, caching video data and reducing the workload of centralized server are introduced to relax well-known limitations with asynchronous transfer and centralized directory service. Moreover, a simple incentive is developed to ensure fair share of peer resources. Packet-level simulations show the benefits of the proposed system in terms of playback continuity, launch delay and server stress.