Sensible policies for QoS-based Service Discovery Protocols in P2P networks

Peer to Peer (P2P) networks allow the interconnection of heterogeneous end-user nodes over the Internet. In a P2P network end-user nodes or peers use Service Discovery Protocols (SDP) to locate services. Due to the nature of different services in the network, there is the problem of providing Quality of Service (QoS) to the peers. Current SDPs do not provide QoS. In this paper, we introduce a novel service discovery protocol, called 'Extended Service Discovery Protocol' (ESDP). This ESDP discovers services through queries to the network, which are propagated using 'Sensible Routing'. Through this routing method QoS awareness is achieved among peers. Through an event-driven simulation study we compare the achieved QoS of the proposed sensible policies with other approaches, such as random and greedy algorithms. Simulation results show that our ESDP: 1)allows a better performance in terms of search time; 2)provides a high probability of success; 3)keeps 1 the overheads to a minimum; and 4)improves the received QoS.