Overlay networks have received a lot of attention due to the recent wide-spread use of peer-to-peer (P2P) applications such as SETI, Napster, Gnutella, and Morpheus. Through replications at numerous peers, digital content can be distributed or exchanged with high resilience and availability. However, existing P2P applications incur excessive overhead on network traffic. For example, Gnutella, w...

Peer-to-Peer (P2P) networks provide a new distributed computing paradigm on the Internet for file sharing. The decentralized nature of P2P networks fosters cooperative and non-cooperative behaviors in sharing resources. Searching is a major component of P2P file sharing. Several studies have been reported on the nature of queries of World Wide Web (WWW) search engines, but studies on queries of...

Peer-to-peer (p2p) systems such as Gnutella and KaZaa are routinely used by millions of people for sharing music and many other files over the Internet, and they account for a significant portion of the Internet traffic. The p2p traffic can be broken down into two categories: protocol messages for maintaining and searching the overlay p2p network, and data messages for downloading data files. T...

Peer-to-peer (P2P) networks have emerged over the past several years as new and effective ways for distributed resources to communicate and cooperate. "Peer-to-peer computing is the sharing of computer resources and services by direct exchange between systems. These resources and services include the exchange of information, processing cycles, cache storage, and disk storage for files." P2P net...

Several aspects of today’s Grids are based on centralized or hierarchical services. However, as Grids increase their size from tens to thousands of hosts, functionalities should be decentralized to avoid bottlenecks and guarantee scalability. A way to ensure Grid scalability is to adopt Peer-to-Peer (P2P) models and techniques to implement nonhierarchical decentralized Grid services and systems...

Past studies have shown the unstability of unstructured peer-to-peer networks and in particular Gnutella. Because of this unstability, queries in these networks are inefficient. Furthermore, to keep the network stable, the protocols used require huge bandwidth usage. One approach proposed by Gnutella conceptors is to create two classes of servents: leaf nodes and ultrapeers. The core of the net...

The dynamics of peer participation, or churn, are an inherent property of Peer-to-Peer (P2P) systems that should be incorporated in both the design and evaluation of P2P systems. This requires a proper characterization of churn in real-world P2P networks. However, the few previous measurement-based studies on the characterization of P2P systems have used either unrepresentative group of peers o...

Abstract. Overlay applications are popular as they provide high-level functionality by masking the intrinsic complexity of the underlay network. However, overlays rely on the underlay 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 net...

In this paper, we describe Credence, a decentralized object reputation and ranking system for large-scale peerto-peer filesharing networks. Credence counteracts pollution in these networks by allowing honest peers to assess the authenticity of online content through secure tabulation and management of endorsements from other peers. Our system enables peers to learn relationships even in the abs...

There is increasing interest in Grids that use compute, storage, and network resources in configurations involving both flexible sharing and tight-coupling. Such usage produces complex dynamics, subject to complex non-linear behavior. We believe that detailed packet level simulation is both possible and necessary forhigh fidelity grid simulations. We present the MicroGrid, a tool set which allo...