Measurement And Analysis On BitTorrent

P2P(Peer-to-Peer) is a new Internet application technology, that has advantages of decentralization, scalability, robustness, load balancing, fault tolerance as so on, compared with the traditional C/S model. BitTorrent(BT) is a typical P2P application protocol. Since it has unique speed and efficiency on the file-sharing, it is more and more attented and applied. However, BitTorrent protocol also has some security and performance deficiencies, that limit its development. The measurements and analysis about BitTorrent can help to understand BitTorrent network users'behavior better, and improve the current BitTorrent protocol and BitTorrent system performance.As the technologies of DHT(Distributed Hash Tables) and PEX(Peer EXChange) advance, BitTorrent system's performance is changing. In order to find BitTorrent system's bottlenecks and improve the system's availability, this article designed and implemented a measurement system based on the combination of active and passive measurement. The measurement system includes Tracker active measurement, DHT active measurement, Peer active measurement, PEX active measurement, Tracker honeypot and entrance passive monitoring. This article is measuring, analyzing characteristics of peers, Trackers and torrents, and construct models. Main modeling tasks are: the popularity of the BT resources modeling, analysis the file size distribution of BT system, Tracker heat, seed heat, popularity of the client software, spended time of finishing downloaded etc, and found that the popularity of the resources to meet the Zipf distribution; by the whole and stage modeling of arrival rate of peers and leaving rate of peers, the article studies the law of Swarm network's development, providing the model for BT network simulator.