Abstract:

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Presented By:
Daniel Stutzbach, Reza Rejaie
Subhabrata Sen

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During recent years, peer-to-peer (P2P) file-sharing sys- tems have evolved in many ways to accommodate growing numbers of participating peers. In particular, new features have changed the properties of the unstructured overlay topology formed by these peers. Despite their importance, little is known about the characteristics of these topologies and their dynamics in modern file-sharing applications. This paper presents a detailed characterization of P2P overlay topologies and their dynamics, focusing on the modern Gnutella network. Using our fast and accurate P2P crawler, we capture a complete snapshot of the Gnutella network with more than one million peers in just a few minutes. Leveraging more than 18,000 recent overlay snap- shots, we characterize the graph-related properties of indi- vidual overlay snapshots and overlay dynamics across hun- dreds of back-to-back snapshots. We show how inaccuracy in snapshots can lead to erroneous conclusions”such as a power-law degree distribution. Our results reveal that while the Gnutella network has dramatically grown and changed in many ways, it still exhibits the clustering and short path lengths of a small world network. Furthermore, its overlay topology is highly resilient to random peer departure and even systematic attacks. More interestingly, overlay dy- namics lead to an onion-like biased connectivity among peers where each peer is more likely connected to peers with higher uptime. Therefore, long-lived peers form a sta- ble core that ensures reachability among peers despite over- lay dynamics.


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http://conferences.sigcommimc/2005/paper...tzbach.pdf