Can ISPs and P2P Users Cooperate for Improved Performance?

By: 
Vinay Aggarwal, Anja Feldmann, and Christian Scheideler
Appears in: 
CCR July 2007

Peer-to-peer (P2P) systems, which are realized as overlays on top of the underlying Internet routing architecture, contribute a significant portion of today’s Internet traffic. While the P2P users are a good source of revenue for the Internet Service Providers (ISPs), the immense P2P traffic also poses a significant traffic engineering challenge to the ISPs. This is because P2P systems either implement their own routing in the overlay topology or may use a P2P routing underlay [1], both of which are largely independent of the Internet routing, and thus impedes the ISP’s traffic engineering capabilities. On the other hand, P2P users are primarily interested in finding their desired content quickly, with good performance. But as the P2P system has no access to the underlying network, it either has to measure the path performance itself or build its overlay topology agnostic of the underlay. This situation is disadvantageous for both the ISPs and the P2P users. To overcome this, we propose and evaluate the feasibility of a solution where the ISP offers an “oracle” to the P2P users. When the P2P user supplies the oracle with a list of possible P2P neighbors, the oracle ranks them according to certain criteria, like their proximity to the user or higher bandwidth links. This can be used by the P2P user to choose appropriate neighbors, and therefore improve its performance. The ISP can use this mechanism to better manage the immense P2P traffic, e.g., to keep it inside its network, or to direct it along a desired path. The improved network utilization will also enable the ISP to provide better service to its customers.

Public Review By: 
Michalis Faloutsos

This paper addresses the antagonistic relationship between overlay/p2p networks and IPS providers: they both try to manage and control traffic at different level and with different goals, but in a way that inevitably leads to overlapping, duplicated, and conflicting behavior. The creation of a p2p network and the routing at the p2p layer are ultimately treading on the routing functions of ISPs. The paper proposes a solution to develop a synergistic relationship between p2p and ISPs: ISPs maintain an “oracle” to help p2p networks in making better choices in picking neighboring nodes. The solution provides benefits to both parties. ISPs become able to influence the p2p decisions, and ultimately the amount of traffic that flows in and out of their network, while p2p networks get performance information for “free.” The reviewers find that the problem is important and the solution is interesting and shows promise. An advantage of the method is that ISPs do not run into legal issues, since they do not engage in caching of potentially illegal content, they just provide performance information.