GNUTELLA

PEER-TO-PEER NETWORKING

GNUTELLA

What is Gnutella Relation to the World Wide Web How it Works Sites / Links / Information

WHAT IS GNUTELLA

Protocol that allows for peer-to-peer networking/communicating

Decentralized applications, were each user can act as a server

General public network, and private networks in isolation or attached to the public ones

Enables transient computers to effectively participate as servers

DEFINITION

WHAT IS GNUTELLA

Search for information anonymously (you control what you look for)

Allows user to determine what information they wish to make public

Can choose what information to share– share nothing– one file– a directory– or your entire hard drive

WHAT IS GNUTELLA

First created by Nullsoft (developers of Winamp)

Protocol developed by them in 1999 Many developers have created compatible

code Gnutella network exists only to the extent that

these developed programs are running and communicating with one another

CREATION

RELATION TO THE WWW

Gnutella hosts are web sites (although transient, equivalent to fetching a file from a web site)

Allows for P2P file sharing, but file transfer is accomplished via HTTP (the same protocol as web browsers and severs)

Each Gnutella application contains a web server component for serving files and a primitive browser element for retrieving them

RELATION TO THE WWW

WWW uses hyperlinks, under the assumption that content remains accessible under a fixed URL and server

Some computers/servers at a given IP address may not be the same, day-to-day, hour-to-hour, minute-to-minute, therefore they are transient

TRANSIENT WEB

RELATION TO THE WWW

Augments HTTP with additional means to locate transient web sites

Traditional search engines cant find transient web sites

Decentralized, so no single responsible company, no central server, and no single point of failure

Anonymous searching (hosts are random users, not dedicated servers / search engines)

ADVANTAGES

RELATION TO THE WWW

Distribution / searching is free, no promo’s. Provides “superdistribution” users who

download content can easily become re-distributors.

ADVANTAGES

RELATION TO THE WWW

Search capability, no guarantee your query will reach the sites/users holding what you seek

Search results are unorganized Puts PC end-user data at risk of unauthorized

or unintentionally authorized exposure. Cascading effect once files are shared or made

available, others can redistribute them Individual nodes/users can become overloaded

since broadcasting info (scaling)

DISADVANTAGES

HOW IT WORKS

You can be a fully functional Gnutella site by installing any of several available clients:

WINDOWSGnucleusBearShareMorpheusSwapper

XoloXLimeWire

Phex

UNIXGnewtelliumGtk-Gnutella

MutellaQtella

LimeWirePhex

MACINTOSHLimeWire

Phex

CONNECTING

HOW IT WORKS

Get connected to WWW Next you have to find a few sites that are

willing to communicate with you:

– some may be friends

– others may be advertised Gnutella sites

CONNECTING

Searching by flooding: If you don’t have the file you want, query 7 of your

partners. If they don’t have it, they contact 7 of their partners, for a

maximum hop count of 10. Requests are flooded, but there is no tree structure. No looping but packets may be received twice. Reverse path forwarding(?) Gnutella Demo: http://

www.capnbry.net/gnutella/ss.phpNote: Play gnutella animation at:

http://www.limewire.com/index.jsp/p2p

HOW IT WORKS

HOW IT WORKS (Gnucleus)

HOW IT WORKS (Gnucleus)

HOW IT WORKS

use key words only do not use astriks, wild cards, dashes,

commas, or periods search results are immediate processed by everyone connected new connections made while searching will

also be searched and results added no re-search function needed

SEARCHING

GNUTELLA: QUERY

Query QueryQ

uery

Query

Query Hit

Query H

itQuery Hit

SITES / LINKS

ADDRESSES

www.gnutella.com

www.openp2p.com

FAQ’s

www.gnutellaforums.com

www.gnutellanews.com

www.gnutelliums.com

GNUTELLA & FREENET Freenet:

– bandwidth and disk space sharing concept for promoting free speech

– very large & geographically distributed hard drive with anonymous access

– Each file is assigned a complex unique identification– To search for files, need to search via that unique identification

code Gnutella:

– Searching and discovery network promoting free interpretation and response to queries

– Gnutella nodes to give hits in the form of filenames, advertising messages, URLs, graphics, and other arbitrary content

CONCLUSIONS

The key challenge of building wide area P2P systems is a scalable and robust location service–Naptser: centralized location service

–*Gnutella: broadcast-based decentralized location service

–*Freenet: intelligent-routing decentralized solution (but correctness not guaranteed; queries for existing items may fail)

REFERENCES

Gnutella– http://gnutella.wego.com

Freenet– http://www.freenetproject.org/index.php?page=icsi-revised– Freenet: A Distributed Anonymous Information Storage

and Retrieval System, Ian Clarke, Brandon Wiley, Oskar Sandberg and Theodore W. Hong\

– www.freenetproject.org– www.oldhat.org/freenet/content.html– P2P Dynamic Networks –

www.developer.com/java/ent/article.php/10933_1496861_1