A Topology-Aware Approach for Distributed Data Reconciliation in P2P Networks

International audienceA growing number of collaborative applications are being built on top of Peer-to-Peer (P2P) networks which provide scalability and support dynamic behavior. However, the distributed algorithms used by these applications typically introduce multiple communications and interactions between nodes. This is because P2P networks are constructed independently of the underlying topology, which may cause high latencies and communication overheads. In this paper, we propose a topology-aware approach that exploits physical topology information to perform P2P distributed data reconciliation, a major function for collaborative applications. Our solution (P2P-Reconciler-TA) relies on dynamically selecting nodes to execute specific steps of the algorithm, while carefully placing relevant data. We show that P2P-Reconciler-TA introduces a gain of 50% compared to P2P-Reconciler and still scales up

A Topology-Aware Approach for Distributed Data Reconciliation in P2P Networks

International audienceA growing number of collaborative applications are being built on top of Peer-to-Peer (P2P) networks which provide scalability and support dynamic behavior. However, the distributed algorithms used by these applications typically introduce multiple communications and interactions between nodes. This is because P2P networks are constructed independently of the underlying topology, which may cause high latencies and communication overheads. In this paper, we propose a topology-aware approach that exploits physical topology information to perform P2P distributed data reconciliation, a major function for collaborative applications. Our solution (P2P-Reconciler-TA) relies on dynamically selecting nodes to execute specific steps of the algorithm, while carefully placing relevant data. We show that P2P-Reconciler-TA introduces a gain of 50% compared to P2P-Reconciler and still scales up

Network coding meets multimedia: a review

While every network node only relays messages in a traditional communication system, the recent network coding (NC) paradigm proposes to implement simple in-network processing with packet combinations in the nodes. NC extends the concept of "encoding" a message beyond source coding (for compression) and channel coding (for protection against errors and losses). It has been shown to increase network throughput compared to traditional networks implementation, to reduce delay and to provide robustness to transmission errors and network dynamics. These features are so appealing for multimedia applications that they have spurred a large research effort towards the development of multimedia-specific NC techniques. This paper reviews the recent work in NC for multimedia applications and focuses on the techniques that fill the gap between NC theory and practical applications. It outlines the benefits of NC and presents the open challenges in this area. The paper initially focuses on multimedia-specific aspects of network coding, in particular delay, in-network error control, and mediaspecific error control. These aspects permit to handle varying network conditions as well as client heterogeneity, which are critical to the design and deployment of multimedia systems. After introducing these general concepts, the paper reviews in detail two applications that lend themselves naturally to NC via the cooperation and broadcast models, namely peer-to-peer multimedia streaming and wireless networkin

Content Distribution in P2P Systems

The report provides a literature review of the state-of-the-art for content distribution. The report's contributions are of threefold. First, it gives more insight into traditional Content Distribution Networks (CDN), their requirements and open issues. Second, it discusses Peer-to-Peer (P2P) systems as a cheap and scalable alternative for CDN and extracts their design challenges. Finally, it evaluates the existing P2P systems dedicated for content distribution according to the identied requirements and challenges

Smart PIN: utility-based replication and delivery of multimedia content to mobile users in wireless networks

Next generation wireless networks rely on heterogeneous connectivity technologies to support various rich media services such as personal information storage, file sharing and multimedia streaming. Due to users’ mobility and dynamic characteristics of wireless networks, data availability in collaborating devices is a critical issue. In this context Smart PIN was proposed as a personal information network which focuses on performance of delivery and cost efficiency. Smart PIN uses a novel data replication scheme based on individual and overall system utility to best balance the requirements for static data and multimedia content delivery with variable device availability due to user mobility. Simulations show improved results in comparison with other general purpose data replication schemes in terms of data availability

Location-Aware Index Caching and Searching for P2P Systems

International audienceUnstructured P2P networks remain widely deployed in file-sharing systems, due to their simple features. However, the P2P traffic, mainly composed of repetitive query messages, contributes the largest portion of the Internet traffic. The principal causes of this critical issue are the search inefficiency and the construction of the P2P overlay without any knowledge of the underlying topology. In order to reduce the P2P redundant traffic and to address the limitations of existing solutions, we propose a solution that performs index caching and efficient query routing while supporting keyword search. We aim at improving the probability of finding available copies of requested files by leveraging file replication. In addition, our scheme tries to direct queries to close results, by using topological information in terms of file physical distribution. We believe that the traffic can be reduced and the user experience ameliorated in terms of faster downloads, with minimum overhead