On the Equivalence of Forward and Reverse Query Caching in Peer-to-Peer Overlay Networks

Abstract

Abstract. Peer-to-peer systems such as Gnutella and Kazaa are used by millions of people for sharing music and many other files over the Internet, and they account for a significant portion of the Internet traffic. The traffic in a peer-to-peer overlay network is different from that in WWW in that each peer is both a client and a server. This suggests that one can deploy a forward cache at the Internet gateway of a network to reduce the amount of queries going outside, or a revere cache at the gateway to reduce the amount of queries going inside, which in turn reduces the queries that are forwarded outside. In this paper, we study the effectiveness of forward and reverse caching at the gateway via analysis and experimental measurement. Our study shows that forward caching and reverse caching at the gateway are equally effective at reducing query and query reply traffic across the gateway.