A currency-based P2P incentive mechanism friendly with ISP

In recent years, peer-to-peer applications are becoming so popular that they contribute great traffic to the Internet. As the P2P overlay topology is oblivious of underlay networks, a large percentage of the P2P traffic is inter-domain traffic, which in turn increases the operating cost of Internet Service Providers (ISPs). To reduce P2P cross-ISP traffic, ISPs have tried various techniques to shape or even block the P2P traffic but get little effect. Recent researches suggest that ISPs should cooperate with P2P systems to solve the problem together by sharing information with each other. In this paper, we propose a novel incentive mechanism that aim at reducing cross-ISP traffic as well as stimulate sharing. We bring the role of ISP in the currency-based incentive, where the incentive mechanism uses virtual currency to prevent free riding and stimulate sharing, at the same time charges a transmission cost for inter-domain traffic. Under such incentive mechanism, the download peer pays the upload peer for the sharing service, and additionally also pays the transmission cost if it incurs any cross-ISP traffic. Simulation results indicate that our incentive mechanism can significantly reduce the cross-ISP traffic as well as improve sharing and decrease free-riding.