A Secure Method for Routing Queries and Dynamic TTL-Based Search in P2P Networks

Abstract

The success of these applications is illustrated by systems such as Napster, Emule, Gnutella, and recently, Bit Torrent. In order to ensure the scalability of these solutions many P2P services operate on top of unstructured overlay networks, which are logical networks deployed at the application level. The approach is shown to be stabilizing the query load subject to a grade of service constraint a guarantee that queries’ routes meet pre-specified class-based bounds on their associated a priori probability of query resolution.  We propose two methods used to improve the search performance in unstructured peer-to-peer networks. The first one is a simple caching mechanism based on resource descriptions. Peers that offer resources send periodic advertisement messages. These messages are stored into a cache and are used for routing requests. The second scheme is a dynamic Time-To-Live (TTL) enabling messages to break their horizon. We show that swap links is the superior random selection approaches: (i) Swap links enables more accurate random selection than does the structured approach in the presence of churn (ii) The structured method is sensitive to a number of hard-to-set tuning knobs that affect performance. Simulation results further show the performance benefits, in terms of mean delay, of the proposed approach. Additional aspects associated with reducing complexity, estimating parameters, and adaptation to class-based query resolution probabilities and traffic loads are studied.