Abstract
Understanding the structural properties of complex peer-to-peer (P2P) networks is essential for their future improvement. It was shown that the performance of a P2P protocol is directly related to its underlying topology. Therefore, multiple efforts have analyzed the topological properties of several P2P systems, including their degree distribution and clustering coefficient. Some obtained results contradict while others coincide. In this work, we closely analyze the topologies of three unstructured P2P systems: BitTorrent, Gnutella, and Freenet and we shed some light on their implications(1).