GNUTELLA

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GNUTELLA

• PEER-TO-PEER NETWORKING

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GNUTELLA

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

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WHAT IS GNUTELLA
DEFINITION

• 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

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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

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WHAT IS GNUTELLA
CREATION

• 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

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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

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RELATION TO THE WWW
TRANSIENT WEB

• 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

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RELATION TO THE WWW
ADVANTAGES

• 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)

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RELATION TO THE WWW
ADVANTAGES

• Distribution / searching is free, no promos.
• Provides superdistribution users who download
  content can easily become re-distributors.

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RELATION TO THE WWW
DISADVANTAGES

• 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)

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HOW IT WORKS
CONNECTING

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

WINDOWS Gnucleus BearShare Morpheus Swapper XoloX
LimeWire Phex
UNIX Gnewtellium Gtk-Gnutella Mutella Qtella LimeW
ire Phex
MACINTOSH LimeWire Phex
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HOW IT WORKS
CONNECTING

• 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

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HOW IT WORKS

• Searching by flooding
• If you dont have the file you want, query 7 of
  your partners.
• If they dont 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.
  php

Note Play gnutella animation at
http//www.limewire.com/index.jsp/p2p
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HOW IT WORKS (Gnucleus)
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HOW IT WORKS (Gnucleus)
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HOW IT WORKS
SEARCHING

• 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

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GNUTELLA QUERY
Query
Query Hit
Query Hit
Query Hit
Query
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SITES / LINKS

• ADDRESSES
• www.gnutella.com
• www.openp2p.com
• FAQs
• www.gnutellaforums.com
• www.gnutellanews.com
• www.gnutelliums.com

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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

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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)

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REFERENCES

• Gnutella
• http//gnutella.wego.com
• Freenet
• http//www.freenetproject.org/index.php?pageicsi-
  revised
• Freenet A Distributed Anonymous Information
  Storageand 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

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Thank You!
End