Measurement and analysis of BitTorrent

Abstract

BitTorrent is assumed and predicted to be the world's largest Peer to Peer (P2P) network. Previous studies of the protocol mainly focus on its file sharing algorithm, and many relevant aspects of the protocol remain untouched. In the thesis, we conduct a number of experiments to explore those untouched aspects. We implement a BitTorrent crawler to collect data from trackers and peers, and statistically analyze it to understand the characteristics and behaviors of the BitTorrent protocol better. We find that the expected lifetime of a peer in the BitTorrent is 56.6 minutes and the activity is diurnal. Peers show strong preference towards a limited number of torrents, and 10% of torrents are responsible for 67% of traffic. The US contributes maximum number of peers to the BitTorrent and µTorrent emerges as the favorite BitTorrent client. We measure the strength of Distributed Denial of Service (DDoS) attack using BitTorrent network and conclude that it is transient and weak. Finally we address and discuss the content locatability problem in BitTorrent and propose two solutions.