Editorial: Peer-to-Peer Networking and Applications, Volume 1, Issue 1

Peer-to-peer (P2P) computing is an emerging model for service distribution. The P2P model has already been established as an important area of distributed computing where an extremely large number of users collaborate and share their resources. In contrast to the traditional centralized server-based service model, i.e., client-server and push models, the P2P model is characterized by cooperation among peers, decentralization, self-organization, and heterogeneity. The notion of client or server is dubious here; instead, any peer is eligible to take the place of any other peer, if the resource constraints are satisfied. P2P computing has attracted great attention from both academia and industry. The introduction of Napster, Gnutella, KaZaA, and BitTorrent not only had an amazing impact on the research community but was also accompanied by overwhelming success among users. Recently, P2P applications for information storage and retrieval, teleconferencing, and audio-video streaming have been appearing. However, there are many challenging and open technical issues to be addressed. Some of these issues are generic in nature and applicable to any P2P application, whereas others are application-specific. Scalability, reliability, convulsions of resources due to constant joining and leaving of peers, security, and misuse from selfish and malicious peers are some of the generic problems. Quality-of-service (QoS) support, coding techniques, and P2P networking architectures are a few issues related to P2P Multimedia-onDemand (MoD) applications. Other P2P applications face a variety of challenges pertaining to the application domains. The aim of the Peer-to-Peer Networking and Applications journal is to publish state-of-the-art research and development results in all subject areas of P2P networking, applications and services in the form of regular papers, tutorials, surveys, case studies and correspondences. In the first issue of Peer-to-Peer Networking and Applications journal, we have included six papers in different areas of P2P networking and applications. In the first paper, “An efficient and scalable framework for content-based publish/subscribe systems”, Zhu and Shen address the challenges of content-based publish-subscribe systems and present an efficient and scalable framework. Subscription information is organized and partitioned dynamically using K-D trees, which enables subscription locality and load balancing. In the second paper, “A survey on peer-to-peer video streaming systems,” Liu, Guo and Liang present a comprehensive survey on P2P live streaming and video-on-demand systems. They also identify the open issues related to P2P video streaming. Selfish peers often misuse their P2P networks by getting services from the peers but providing little or no service to others in return. In the third paper, “Incentive mechanism for the CoopNet network,” Manzato and Fonseca address this issue and propose an incentive mechanism for the CoopNet. A survey on content delivery in P2P systems is presented in the fourth paper, “On peer-to-peer (P2P) content delivery,” where Li discusses different deployed P2P applications and research proposals. Different overlay creation and P2P scheduling techniques are also presented. Various Distributed Hash Table (DHT) techniques have been proposed to achieve efficient lookup in P2P storage systems. In the fifth paper, “DHT routing analysis in a logarithmically transformed space,” Kersch and Szabó develop a general model to analytically describe different Peer-to-Peer Netw Appl (2008) 1:1–2 DOI 10.1007/s12083-007-0005-z