To reduce the searching cost is the key of improving the performance of P2P network. We propose a search algorithm for unstructured P2P network, which is based on query agent. The algorithm can adaptively control the scale of query by satisfactory degree. We carry out simulations under two query-replication modes and the simulation results show that the algorithm can effectively decrease the redundant cost. The mobility of query agent assures that the repeat messages are trivial.
A mechanism, E-SDR is proposed to enhance salvaging performance for Dynamic Source Routing (DSR). In this mechanism, salvaging is processed not by only one node as in traditional DSR, but also its neighbor ones. Through this kind of co-operation among neighbor nodes, the probability of salvaging a packet can be increased. Hence, higher routing performance can be achieved. We implement the mechanism in NS-2 as a patch of DSR, and compare E-DSR to traditional DSR. The results show that, this mechanism can improve traditional DSR routing performance significantly, especially as nodes and traffic are accruing.