Performance of BitTorrent-Like P2P File Sharing Systems inspired by ALTO

Abstract

The Peer-to-Peer (P2P) file sharing system, most notably BitTorrent (BT), have achieved tremendous success among Internet users. Recent studies suggest that the long-term relationships among BitTorrent peers can be explored to enhance the downloading performance. In such systems, The mechanisms like tit-for-tat, optimistic unchoking, anti-snubbing, various piece and selection strategy have been working very well. We design a new scheme to improve the performance of BitTorrent-Like P2P File Sharing Systems, inspired by the idea of Application Level Traffic Optimization (ALTO). This work is an attempt to study the performance of BitTorrent protocol and its networking infrastructure through two strategies, (A) we propose a novel approach to make BitTorrent node aware of the topology of underlying networks. Then we modify BitTorrent's original algorithms and replace them with new localized algorithms based on autonomous system (AS) hops. (B) we conduct comprehensive experiments to verify the correctness and effectiveness of our scheme based on the PeerSim simulation. The simulation result shows that, with our scheme, nodes in BitTorrent-like systems have better sense of the topology of their underlying networks, and can interact more efficiently. Besides, our scheme can help to decrease the traffic, optimize traffic distribution across the whole networks, and obtained are used to infer various performance parameters of BitTorrent protocols.