Understanding lookup performance deficiencies in the KAD network

The KAD network is one of the largest distributed hash tables utilized by the popular P2P file-sharing systems: aMule and eMule. However, its lookup performance is recognized as inefficient. In this work, based on the fact that peers publish and retrieve information with the help of their routing tables and publishing tables, we evaluate this inefficiency problem via a series of real world tests. Our measurements show that even though the maintenance policy of routing tables is well designed, the current refresh scheme of the publishing table and the selfishness of publishing peers cause the poor lookup performance. To mitigate this problem, we propose there different modifications and analyze their advantages and weaknesses.