Computer and Communication

European Transactions on Telecommunications, 2004

Peer-to-peer (P2P) services evolved to the most popular applications in today's Internet. In particular, P2P networks became very popular amid the relentless spread of Gnutella, Kazaa, eDonkey and BitTorrent file sharing applications. Remarkably, only very simple protocols and almost no support by the transport network was required to make these distributed services operable on a large scale in very little time. P2P entails a highly attractive paradigm in distributed computing: P2P is based on communication between equals. The peers are highly autonomous. P2P services provide simple and efficient mechanisms to pool and share exchangeable resources like CPU cycles, disk space or content. These features facilitate that any peer can be removed without resulting in a complete loss of service, in contrast to the traditional client/server concept, where a failure of the central control entity may corrupt the service completely. A further reason for the notable success of P2P is that these networks operate on the application level and typically form application-specific overlays. P2P overlays work without particular network or transport support, and can be run completely at the edge of a network. They apply self-organizing principles and special routing schemes to locate and exchange resources. While P2P overlays do implement a certain type of group communication structure, they do not suffer from the same deployment difficulties as multicast services did in the past. The P2P mode of operation however, also has some downsides. P2P protocols cause higher traffic volumes, including data traffic as well as signaling traffic, since the peers need to synchronize. P2P network topologies reveal high variability and traffic patterns of P2P applications fluctuate considerably in time and space. Traditional network design techniques and traffic engineering procedures have to be validated to work in the P2P context before they are applied. New engineering methods may be required in order to maintain the autonomous and self-organizing characteristics of P2P and to provide appropriate service stability, quality and efficiency for P2P services. The aim of this special issue of the European Transactions on Telecommunication is to present very recent, outstanding research work on P2P networks and P2P services. The Call for Paper resulted in the submission of 42 papers from Europe, the United States and the Asian-Pacific region. The editor team has selected eight of these submissions after a thorough review process and extensive discussions for publication in this special issue. The guest editor team of this ETT special issue would also like to thank the publisher, the reviewers and the authors for their efforts and flexibility to produce, review and finalize this special issue in a very short time frame. We hope that this special issue may serve to promote further research in this new and popular area of telecommunication. The contribution of Azzouna and Guillemin evaluates the impact of P2P applications on traffic in wide area networks. The authors analyze measurements taken on a high speed IP backbone link carrying P2P applications traffic towards several ADSL areas. They observe that the prevalent part, the traffic is caused by P2P applications (almost 80% of total traffic) and that the usage of network becomes highly symmetric. Since long lasting TCP connections of P2P applications have a rather small bit rate and do not show evidence for long range dependency, the global traffic can be described by means of usual teletraffic models based on M=G=1 queues with Weibullian service times. The paper of Schollmeier and Schollmeier investigates P2P traffic by a graph theoretical study of the properties of P2P overlays. Analytical topology models for infinite and finite random networks are used to derive performance characteristics for P2P protocols and to evaluate the effect of introducing centralized entities, such as superpeers. Cholvi, Felber and Biersack propose novel mechanisms for improving the search efficiency in unstructured P2P networks. The mechanism is based on peers performing local dynamic topology adaptations, which are derived from query traffic patterns. The topology adaptation creates spontaneously semantic communities, i.e. groups of peers that share similar interests, in which file requests are fulfilled more efficiently. Copyright # 2004 AEI Wierzbicki et al. investigate the possibility of caching of files in P2P file sharing applications. They show that the file popularity in P2P file sharing networks does not follow Zipf's law and that P2P file sharing traffic differs strongly from well-studied web traffic. The results are used to investigate the efficiency of different cache management policies for the FastTrack P2P file sharing protocol. Sasabe et al. investigate scalable media search and in-time retrieval methods based on a P2P network architecture. The method is able to achieve continuous media play-out for popular media streams without introducing extra load on the system. The authors also investigate the failure of LRU cache replacement algorithms for continuous media play-out of unpopular media streams and propose a biological-inspired cache replacement mechanism that considers the balance between supply and demand for media streams. The algorithm can adapt easily to changes in the popularity of media streams. Kumar et al. present a P2P network based on a butterfly overlay topology. The diameter of this overlay achieves a theoretical lower bound of log n=log n log n, if the average routing table size is not more than log n. Compared to existing DHT schemes, the diameter is reduced by a factor of log log n. This reduction translates into the same amount of reduction on query latency and average traffic per node. The authors show that the proposed scheme maintains the same level of robustness as existing DHT schemes. Yamada, Hoshiai and Kimura propose brokerless trust and reputation mechanisms for the COMNet P2P framework. COMNet is an intelligent community spaces architecture, which supports the activation of communities through P2P technology. The proposed trust and reputation algorithms are solely based on information from other peers. Bisignano, Di Modica and Tomarchio present a framework for mobile P2P applications, which combines P2P ad hoc communication with the capabilities of small mobile units. The framework is designed for J2ME enabled mobile devices in an infrastructure-less environment. One of the key features of the framework is the interoperability with JXTA, a wellknown P2P open platform. A simple but effective example of application is provided showing the viability of the designed framework.

Problem Statement: Peer to Peer (P2P) systems have grown dramatically in recent years. The most popular type of P2P systems are file sharing networks, which are used to share various types of content over the Internet. Due to the increase in popularity of P2P systems, the network performance of these systems has become a very important issue in the design and realization of these networks. Hence, the performance of the P2P has been improved. Approach: This paper suggests the following methods for the improving the performance of P2P systems: Method-1: Improving the P2P routing using a sandwich technique. Method-2: Improving the search performance by introducing a new searching method based on the super peer. Method-3: Improving the search by introducing a ranking algorithm based on the knowledge database. Results: The system demonstrates that the methods introduced here have improved the performance of P2P network efficiently when compared to the existing methodologies. Conclusions / Recommendations: The performance of the P2P systems have improved by using the above said methods, hence the traffic can be reduced in P2P network.

2002

In this document we study the problem of reducing bandwidth utilization in file sharing peer-to-peer (P2P) networks. First we describe the various aspects of peerto-peer computing that make it attractive over client-server computing. Then, we examine the environmental characteristics of a P2P system in deployment. We explore some orthogonal factors that need to be considered when constructing a bandwidth-efficient P2P framework. These include the distribution of control in the system, routing, and caching and replication mechanisms. We follow this with a description of a number of P2P architectures, including indexing-based schemes, flooding-based schemes, hashing-based schemes, and a publish/subscribe-based scheme, and their advantages and disadvantages are qualitatively examined. Finally, we put forth a number of proposals on the topics of multidimensional P2P routing, wireless P2P networks, web services and P2P, and what Internet Service Providers (ISP) can do to reduce bandwidth consumption by poor-quality P2P file sharing systems. iii A BLOOM FILTER SUMMARIES REFERENCES 2.3. MISREPORTING from other peers, which would otherwise consume valuable network resources. This is particularly important to low bandwidth users, who have smaller amounts of network resources to start off with. However, it should be noted that an alternate explanation is that users are concerned about the legality of the files that they are sharing [1]. Future systems may be able to directly measure or verify reported information.

IEEE Communications Magazine, 2000

2012

In order to fully utilize the stable edge transmission capability of CDN and the scalable last-mile transmission capability of P2P, while at the same time avoiding ISP-unfriendly policies and unlimited usage of P2P delivery, some researches have begun focusing on CDN-P2P-hybrid architecture and ISP-friendly P2P content delivery technology in recent years. In this paper, we first survey CDN-P2P-hybrid architecture technology, including current industry efforts and academic efforts in this field. Second, we make comparisons between CDN and P2P. And then we explore and analyze main issues, including overlay route hybrid issues, and playing buffer hybrid issues. After that we focus on CDN-P2P-hybrid model analysis and design, we compare the tightlycoupled hybrid model with the loosely-coupled hybrid model, and we propose that there are some main common models which need further study. At last, we analyze the prospective research direction and propose our future work.

ArXiv, 2010

Over the last decade, internet has seen an exponential increase in its growth.With more and more people using it, efficient data delivery over the internet has become a key issue. Peer-to-peer (P2P)/seed sharing based networks have several desirable features for content distribution, such as low costs, scalability, and fault tolerance. While the invention of each of such specialized systems has improved the user experience, some fundamental shortcomings of these systems have often been neglected. These shortcomings of content distribution systems have become severe bottlenecks in scalability of the internet.In order to combine the desired features of classical Content Distribution Networks (CDNs) and P2P/seed sharing based networks, we propose a hybrid CDN structure with a P2P/seed sharing based streaming protocol in the access network . In this work, we focus on the problem of data redundancy (at each node) and show how severely it impacts the network economics and the experience o...

Information Systems, 2011

Content distribution networks (CDN) are fundamental, yet expensive technologies for distributing the content of web-servers to large audiences. The P2P model is a perfect match to build a low-cost and scalable CDN infrastructure for popular websites by exploiting the underutilized resources of their user communities. However, building a P2P-based CDN is not a straightforward endeavor. In contrast to traditional CDNs, peers are autonomous and volunteer participants with their own heterogeneous interests that should be taken into account in the design of the P2P system. Moreover, churn rate is much higher than in dedicated CDN infrastructures, which can easily destabilize the system and severely degrade the performance. Finally and foremostly, while many P2P systems abstract any topological information about the underlying network, a top priority of a CDN is to incorporate locality-awareness in query routing in order to locate close-by content. This paper aims at building a P2P CDN with high performance, scalability and robustness. Our proposed protocols combine DHT efficiency with gossip robustness and take into account the interests and localities of peers. In short, Flower-CDN provides a hybrid and locality-aware routing infrastructure for user queries. PetalUp-CDN is a highly scalable version of Flower-CDN that dynamically adapts to variable rates of participation and prevent overload situations. In addition, we ensure the robustness of our P2P CDN via low-cost maintenance protocols that can detect and recover from churn and dynamicity. Our extensive performance evaluation shows that our protocols yield high performance gains under both static and highly dynamic environments. Furthermore, they incur acceptable and tunable overhead. Finally we provide main guidelines to deploy Flower-CDN for the public use.

Recent Advances

Video transmission over IP is currently a hot topic both in entertainment and research communities. A problem that threatens the development of video over IP services is the bandwidth required to serve a potentially very large number of users. In this context, Peer-to-peer (P2P) technologies are considered a possible solution for the distribution of video content to many users. This chapter describes a novel P2P transport protocol suited for live multimedia streaming. The described protocol has low start-up time, it is robust with respect to data losses (due to congestion or node departure) and it can help counteracting the malicious injection of “bogus packets” in the media stream. The proposed protocol can be used with any type of data and, from the application point of view, it appears as a protocol similar to TCP or UDP, making the reuse of existing software and protocols easier.

… Information Networking and …, 2005

A peer-to-peer (P2P) network is composed of large number of peer computers which are cooperating by exchanging messages in networks. In multimedia streaming applications, multimedia data is required to be efficiently and reliably delivered to ...