Characterization of BitTorrent Swarms and Their Distribution in the Internet
The optimization of overlay traffic resulting from applications such as BitTorrent is a challenge addressed by several recent research initiatives. However, the assessment of such optimization techniques and their performance in the real Internet remains difficult. Despite a considerable set of works measuring real-life BitTorrent swarms, several characteristics of those swarms relevant for the optimization of overlay traffic have not yet been investigated. In this paper, the authors address this lack of realistic swarm statistics by presenting their measurement results. In particular, they provide a statistical characterization of the swarm sizes, the distribution of peers over Autonomous Systems (AS's), the fraction of peers in the largest AS, and the size of the shared files.