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Gnutella presentation by ReF5Xi

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									GNUTELLA

PEER-TO-PEER NETWORKING
GNUTELLA

   What is Gnutella
   Relation to the World Wide Web
   How it Works
   Sites / Links / Information
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
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
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
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
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
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)
RELATION TO THE WWW
ADVANTAGES
   Distribution / searching is free, no promo’s.
   Provides “superdistribution” users who
    download content can easily become re-
    distributors.
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)
HOW IT WORKS
CONNECTING
   You can be a fully functional Gnutella site by
    installing any of several available clients:

    WINDOWS
    Gnucleus          UNIX
    BearShare     Gnewtellium
    Morpheus      Gtk-Gnutella    MACINTOSH
                    Mutella         LimeWire
     Swapper                          Phex
      XoloX          Qtella
    LimeWire       LimeWire
      Phex           Phex
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
   HOW IT WORKS
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.php
            Note: Play gnutella animation at:
            http://www.limewire.com/index.jsp/p2p
HOW IT WORKS (Gnucleus)
HOW IT WORKS (Gnucleus)
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
GNUTELLA: QUERY


                                    Query




                      Query Hit
                                   Query Hit
              Query


  Query Hit
   Query                          Query
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

								
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