Research and Analysis of the Optimization of the Unstructured P2P Overlay Networks

Unstructured P2P systems are self-organized and decentralized. However, the mechanism of a peer randomly joining and leaving a P2P network, loose overlay structure, and little control over resources causes topology mismatching between the P2P logical overlay network and the physical underlying network, which brings great stress on the Internet infrastructure and seriously limits the performance gain from various search or routing techniques. Therefore, the overlay optimization techniques are thus of great importance to unstructured P2P systems, mainly due to the characteristics of unstructured P2P overlays discussed above. This paper presents a research on existing overlay optimization techniques for unstructured P2P systems. Detailed analysis is also presented. At last, based on the discussion, this paper outlines future research directions.