Examining Graph Properties of Unstructured Peer-to-Peer Overlay Topology

During the past few years, unstructured peer-to- peer (P2P) file-sharing systems have witnessed a significant increase in popularity. However, there lacks a systematic study on graph properties of the overlay topology. In this paper, we use accurate snapshots of the Gnutella overlay that span over roughly three years to explore changes in graph properties over long timescale. We investigate the effect of network address translation (NAT) on topology analysis. We examine a wide spectrum of graph properties characterizing the Gnutella top-level overlay topology and illustrate some interesting results. We find that the connection limit plays an important role in forming the unstructured overlay topology.