Design and analysis of ISP-friendly file distribution protocols

In recent years, BitTorrent-like file-swarming applications are becoming so popular that they contribute to a large percentage of the current Internet traffic. Internet service providers (ISPs) not only need to cope with this traffic engineering problem, e.g., when and how to increase their network capacity, but more importantly, these P2P applications also increase their operating cost since large amount of the traffic has to go through the cross-ISP links. In this paper, we consider the design and analysis of an ISP-friendly file swarming protocol so as to reduce the cross-ISP traffic. We analytically show that the conventional P2P file-swarming protocols consume significant bandwidth on the cross-ISP links. We also derive an upper and lower bound for the cross-ISP traffic for ISP-friendly protocols which exploit the data locality property. We propose and implement an ISP-friendly protocol and carried out large scale experiments on the PlanetLab. Experimental results indicate that our protocol can significantly reduce the cross ISP-traffic and provide a reasonable file downloading time.