Peer-to-Peer Tauschbörsen: Eine Protokollübersicht
Key: HSS02-3
Author: Oliver Heckmann, Jens Schmitt, Ralf Steinmetz
Date: November 2002
Kind: @techreport
Abstract: This article sheds light on the technical background as well as the detailed working of popular peer-to-peer file sharing systems. The first large-scale peer-to-peer file sharing system, Napster, is reviewed. Henceforth, the eDonkey protocol, which is very popular for sharing videos, is presented in detail. The principles and mechanisms that lie at the heart of eDonkey are typical for the latest, successful peer-to-peer file sharing systems. Of course, an overview of peer-to-peer file sharing systems would not be complete without Gnutella, the first "real" peer-to-peer system without any server elements. The protocol details as well as the many problems with which Gnutella initially had to cope are described. Next, the currently most popular peer-to-peer protocol, the Fasttrack protocol, is presented. Along with all these protocols, measurement results from experiments we conducted with the different systems are reported. Comparing the evolution of the different systems several parallels become evident. Modern, well-performing systems apply the same principles and mechanisms: hashes to identify and locate identical files in order to allow for simultaneous downloads from several locations as well as continuation of interrupted downloads, so-called supernodes or, more explicitly, servers to enable efficient searching as well as mechanisms to increase fault-tolerance in case of failures of these nodes. In addition, we discuss why - apart from notable exceptions like Freenet und Filetopia - so far the anonymity of participants in peer-to-peer file sharing systems has been neglected and why this will become important in the future. Peer-to-peer is an interesting and timely research field, hence we review some of the most interesting work in this area at the end of the article. The article is written in german.
View Full paper (PDF) | Download Full paper (PDF)

The documents distributed by this server have been provided by the contributing authors as a means to ensure timely dissemination of scholarly and technical work on a non-commercial basis. Copyright and all rights therein are maintained by the authors or by other copyright holders, not withstanding that they have offered their works here electronically. It is understood that all persons copying this information will adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder.