Neighborhood Filtering Strategies for Overlay Construction in P2P-TV Systems: Design and Experimental Comparison

Peer-to-Peer live-streaming (P2P-TV) systems aim at disseminating real time video content using Peer-to-Peer technology. Their performance is driven by the overlay topology, i.e., the virtual topology that peers use to exchange video chunks. Several proposals have been made in the past to optimize it, yet few experimental studies have corroborated results. The aim of this paper is to provide a comprehensive experimental compar- ison based on PeerStreamer, in order to benchmark different strategies for the construction and maintenance of the overlay topology in P2P-TV systems. We present only experimental results in which fully-distributed strategies are evaluated in both controlled experiments, and in the Internet, using thousands of peers. Results confirm that the topological properties of the overlay have a deep impact on both user quality of experience and network load. Strategies based solely on random peer selection are greatly outperformed by smart, yet simple and actually im- plementable strategies. The most performing strategy we devise guarantees to deliver almost all chunks to all peers with a play- out delay as low as 6 seconds even when system load approaches 1, and in almost adversarial network scenarios. PeerStreamer is Open Source to make results reproducible and allow further research by the community.