Two Propositions about Geographical Distributions of BitTorrent File Resources

Recently, much attention has been paid to applying underlay information in optimizing BitTorrent (BT) systems. However, most of these approaches have taken such an assumption that BT file resources are distributed uniformly on the earth, which directly results in performance degradation on BT. In this paper, we study the geographical distribution of BT file resources. By measuring and analyzing BT systems, BT file resources are found to be non-uniformly distributed both in country level and AS level. Consequently, two propositions about the characteristics of geographical distribution of BT files resources are derived. These propositions overthrow the foundation based on which many P2P locality-based algorithms used to optimize cross ISPs traffic, i.e., BT file resources were thought to follow uniform distributions geographically. Finally, a general and adaptive traffic optimizing algorithm called GeoDTO is proposed and analyzed.