In this paper we introduce a random-graph based model for studying the evolution of ad hoc peer-to-peer (P2P) communities such as in Gnutella or Freenet. The proposed random graph model generates a nonuniform graph and provides control over the nodal degree distribution. We study basic properties such as reachability from a given node in the network using an analytical approach. The model can b...

We describe a new animation technique for supporting interactive exploration of a graph, building on the wellknown radial tree layout method. When a node is selected to become the center of interest, the visualization performs an animated transition to a new layout. Our approach makes the transition easy to follow by linearly interpolating the polar coordinates of the nodes and enforcing constr...

We describe a new animation technique for supporting interactive exploration of a graph, building on the wellknown radial tree layout method. When a node is selected to become the center of interest, our visualization performs an animated transition to a new layout. Our approach is to linearly interpolate the polar coordinates of the nodes, while enforcing constraints on the layout to keep the ...

Peer-to-peer systems have become one of the most popular Internet applications. Some unstructured systems such Gnutella perform file searching by flooding requests among nodes. It has been proven that such unstructured systems are not scalable, and searching consumes tremendous bandwidth. We propose three mechanisms to reconstruct the system topology and improve message flooding. Our research a...

Unstructured P2P networks support distributed applications whose workload may vary significantly over time and between nodes. Self-optimizing systems try to keep the load in the network balanced despite the frequent load fluctuations. Several P2P systems exhibit a number of related features but fail to avoid centralization under high-load situations. ERGO aims to balance the overloaded nodes by...

We present the design and prototype of GnuStream, a peerto-peer (P2P) and receiver-driven media streaming system. GnuStream is built on top of Gnutella, and it integrates dynamic peer location and streaming capacity aggregation. Each GnuStream streaming session is controlled by the receiver peer and involves a dynamic set of peer senders instead of one fixed sender. The receiver aggregates stre...

In the design and implementation of the overlay architecture most peer-to-peer (P2P) systems rely on the underlay network to provide them with basic connectivity. Therefore, the intrinsic features of the underlay network determine the efficiency of the overlay. Accordingly, studying the interdependency of the overlay and underlay networks leads to a better understanding of P2P behaviour. We pre...

content discovery is one of the fundamental issues that determines the architecture and performance of content distribution networks based on peer-to-peer (p2p) networks. to administrate the costs and discoveries, peers of a p2p network communicate with each other by one or more overlay layers. the condition of node’s relations in overlay networks, have a great impact in efficiency of networks....

For the last few years Peer-to-Peer (P2P) systems have been used for cooperative file sharing among users. Napster was the first system that allowed the exchange of music files through the collaboration of it’s peers. P2P systems make an effective use of the widespread availability of computing and storage resources that are present over the Internet, even though temporarily. The ability to sea...

Peer-to-peer (P2P) systems have become popular as a means of sharing resources efficiently within large sets of end-user platforms. Among their many applications are file sharing [4, 8], storage [10] and Voice-over-IP (VoIP) [12]. Ideally, such systems should be able to perform well even when the peers are heterogeneous with respect to performance-critical attributes such as bandwidth or storag...