Author(s)

Lin Ye, Hongli Zhang, Fei Li, Majing Su

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Measuring and characterizing peer-to-peer (P2P) file-sharing systems will benefit the optimization and management of P2P systems. Though there are a lot of measurement studies on BitTorrent almost in every important aspect, few of them focus on the measurement issues and the corresponding solutions, which can strongly influence the accuracy of measurement results. This paper analyzes the key difficulties of measuring BitTorrent and presents a measurement system with combination of active and passive ways, which can han-dle with the problems well and balance the efficiency and integrity. Then compared to other work, a more complete and representative measurement was performed for nearly two months and several characteristics are concerned: 1) there are diverse content sharing in BitTorrent system, but multimedia files that are larger than 100 MB are the most. 2) Distributed Hash Tables has indeed enhanced the ability of peer discovery though there are some pitfalls to be addressed. 3) Pieces are distributed uniformly after the early stage and there are few rare pieces. Furthermore, peer arrival rate shows a periodical pattern, which was not well mod-eled before. Then an improved model is proposed and the experiment results indicate that new model is fitted in with actual measurement results with high accuracy.

P2P, BitTorrent, Measurement, Peer, Piece

L. Ye, H. Zhang, F. Li and M. Su, "A Measurement Study on BitTorrent System," International Journal of Communications, Network and System Sciences, Vol. 3 No. 12, 2010, pp. 916-924. doi: 10.4236/ijcns.2010.312125.