iDTT: Delay Tolerant Data Transfer for P2P File Sharing Systems

As the dominant Internet application, peer-to-peer (P2P) file sharing systems account for the major portion of Internet traffic, posing significant burden on ISPs. Many ISPs have attempted to discriminate against P2P traffic, making it important to alleviate such severe conflict. In this paper, we propose a novel architecture called iDTT that aims to use the underutilized off-peak time network capacity to transfer data for P2P file sharing systems. The rationale is that file sharing, especially for large files, is not real-time and able to tolerate some delay. iDTT is able to reduce network usage at peak time by storing data at overlay nodes and transferring it at off-peak times. This reduces ISP cost for transit traffic and the pressure on their infrastructure. Two representative P2P systems, eMule and BitTorrent, are adapted to use iDTT as their data plane. Our experiments on Emulab show that iDTT significantly reduces the network traffic at peak times while only slightly increasing the downloading time for these applications.