Peer-to-Peer (P2P) NetworksPeer-to-Peer (P2P) Networks

By Bongju Yu

ContentsContents

What is P2P? Features of P2P systems P2P Architecture P2P Protocols P2P Projects Reference

What is P2P ?What is P2P ?

P2P is Peer-to-Peer. Sharing of computer resources and services

by direct exchange between systems. Resources including the exchange of

information, processing cycles, cache storage, and disk storage for files.

Features of P2P systemsFeatures of P2P systems

Distributed computing and resources Collaboration Intelligent agents Core technologies

P2P ArchitectureP2P Architecture

Computers that have been used as clients communicate directly among themselves and can act as both clients and servers.

Two basic models of P2P technology Server dependant True P2P

Server dependantServer dependant

Considered as centralized since it holds a catalog of addresses.

The addresses are referenced by a set of indexes that determine the appropriate address set.

A classic example : Napster

True P2PTrue P2P

This type has every node as a Peer, and lacks a central router.

The routing structure either is a distributed catalog which uses indexes as parameters or direct messaging where the message is sent to a peer group until the inquiry is found.

The popular example : Gnutella

P2P ProtocolsP2P Protocols

Connection Establishment Search and Download TTL (Time To Live)

P2P ProjectsP2P Projects

Napster Scour Gnutella Freenet

NapsterNapster

The most popular P2P file-sharing program. Lacking many of the advanced features of

other P2P programs and limiting its file sharing capabilities to MP3 files only.

The first to be hit by lawsuits, Napster is still involved in legal battles.

ScourScour

Very popular with the second largest user base.

Users could share files of type MP3, video, and documents.

After the developments in Napster's case, and facing impending court cases, decided to shut down.

GnutellaGnutella

The first "true" P2P program. Files of any type can be shared. To facilitate

file sharing, messages are sent between end hosts.

Plagued with slow searches and a need for high bandwidth connections.

FreenetFreenet

Cannot be detected what files a user has downloaded or uploaded from the Freenet network.

Employing intelligent routing techniques superior to Gnutella.

If a user that was sharing files goes offline, his files remain available to download.

ReferenceReference1. Geoffrey Fox, “Peer-to-Peer Networks”, Computing in Science &

Engineering, Volume 3, Issue 3, Page 75 - 77, 2001. 2. Manoj Parameswaran, Anjana Susarla and Andrew B. Winston,

“P2P Networking: An Information-Sharing Alternative”, Computer, Volume 34, Issue 7, Page 31 - 38, 2001.

3. Andy Oram, “Peer-To-Peer: Harnessing the Benefits of a Disruptive Technology”, O’Reilly & Associates, Inc., 2001.

4. David Wiley, “Peer-to-Peer and Learning Objects: the New Potential for Collaborative Constructivist Learning Online”, Proceedings IEEE International Conference on Advanced Learning Technologies, Page 494 - 495, 2001.

Thank you!Thank you!

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