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Peer-to-Peer Communication
Research Project Presentation 2002
CIS 585
– Sukmin Kim
– Srikara Hrushikesh
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Presentation Contents
 Introduction
 Current Web Issues
 P2P Business Implications
 Concerns with P2P
 P2P Architecture
 Napster
 Gnutella
 Freenet
 Future of P2P
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Introduction
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Introduction to P2P
 Direct communication between peers
– Not a Client/Server Architecture
 History traces back to 1979
– Modem
 Popularity from Napster
 Acceptance in Business Community
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Current Web Issues
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Current Web Issues
 Cavalier attitude towards users
– Policy regarding usage of customer data
 Accountability
– Loss of e-mail lists and files
 Hackers
– TCP/IP related issues
 P2P attempts to solve, but will not
solve all the problems
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P2P Business Implications
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P2P Business Solutions
 When it comes to business P2P is like any fledging
technology. It has shown lot of promise, but has
encountered lot of hurdles
 P2P Solutions include
–
–
–
–
–
File Sharing
Distributed computing
Collaboration
Messaging
C2C e-commerce
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Industry Players
 File Sharing
– Gnutella
– Nextpage
www.gnutelliums.com
www.nextpage.com
 Collaboration
– Groove Networks
– Omniprise
www.groove.net
www.ikimbo.com
 Distributed Computing
– SETI@home
www.distributed.net
 C2C e-commerce
– Lightshare
www.lightshare.com
 Direct e-mail
– WorldStreet
www.worldstreet.com
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Specific Business Applications
 Health Care
– Santa Barbara County Health care Department
 Law Firms
– Chicago based law firm Baker & McKenzie
 Pharmaceutical Industry
– GlaxoSmithKline research center
 Chip Manufacturing
– Intel’s NetBatch
 Investment Banking
– Bear, Stearns
Source: PC Magazine, “Peer Pressure” by Sarah L. Roberts, 06/26/01
PC Magazine, “Peer-to-Peer” by Cade Metz, 06/01/01
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P2P Business Model
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P2P Practical Model of Enterprise
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Concerns with P2P
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Concerns with P2P
 Need for more Bandwidth
 Always on Servers result in higher net
connectivity.
 The current asymmetry of more download
and less upload will change
 Serious security issues
 Free-Riding effect
 Copyright and Royalty violations
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P2P Architecture
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Napster
 Online Music Sharing Business
 The software was written by 19 year old guy
named Shawn Fanning
 Company recently filed for bankruptcy
 Not a complete P2P
 Napster uses servers to hold indexes that
store file locations
 The addresses of the Napster nodes bypass
the DNS system
 After resolving the IP address, the file transfer
control shifts to nodes
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Napster Model
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Gnutella
 Currently the most popular decentralized
P2P file sharing program
 Decentralized, No dependency on central
server
 No website connection
 Utilizes daisy-chain effect for communication
 Allows sharing of all kinds of digital files
 Able to reach every computer on the internet
 Survival capability is high
– can not be brought down
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Origin of Gnutella
 Gnutella = GNU project of the Free Software Foundation
+ Nutella (the hazelnut/chocolate spread)
 Originally designed by Nullsoft, a subsidiary of AOL
 AOL halted Nullsoft's development of the Gnutella
 Gnutella was downloaded during few hours
 Programmers reverse-engineered and created their own
Gnutella software
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Comparison
Between Gnutella & Napster
Napster Model
Gnutella Model
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Gnutella Process
1.
Search Request
User A sends out a 1st layer
request to computers B, C, & D.
2.
Search Relay
Users B, C, & D send the request
on to the next layer of connected
computers.
3.
Search Response
The file is located and a
response is sent to computer A
via the same pathway.
4.
Download
The file is then downloaded by A
through a direct http connection.
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Gnutella Terms
 Servent
A combination of a server and a client. In the decentralized
gnutella model, each computer on the network is both a
client and a server.
 Time to Live
Abbreviated "TTL," the Time to Live is the number of hops
that a message will make on the Gnutella Network before
being discarded. Each servent that views a message will
decrement its TTL by 1, and will discard that message when
the TTL reaches 0. This prevents messages from being sent
back and forth across the Gnutella Network indefinitely. Most
gnutella clones set TTL at around 7, although some allow the
user to configure it.
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Gnutella Terms (Continued)
 Ping
When a new user joins the Gnutella Network, he broadcasts a
message called a "ping request" to the network, announcing his
presence on the network. Nodes which receive this ping, send a
“Pong” back to the pinging user to acknowledge that they have
received this message.
 Pong
When a node on the Gnutella Network receives a ping request,
it replies with a pong (a.k.a ping response). This pong contains
the responding host's IP address and port, as well as number of
files the responding host is sharing and their total size.
 Horizon
Horizon is the group of gnutella servents that the node is
capable of communicating with at a particular time.
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FreeNet
 Freenet is an open, democratic system which cannot
be controlled by any one person, not even its
creators.
 Freenet is a large-scale peer-to-peer network which
pools the power of member computers around the
world to create a massive virtual information store
open to anyone to freely publish or view information
of all kinds.
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FreeNet is
 Highly survivable
All internal processes are completely anonymized and
decentralized across the global network, making it virtually
impossible for an attacker to destroy information or take control of
the system.
 Private
Freenet makes it extremely difficult for anyone to spy on the
information that you are viewing, publishing, or storing.
 Secure
Information stored in Freenet is protected by strong cryptography
against malicious tampering or counterfeiting.
 Efficient
Freenet dynamically replicates and relocates information to provide
efficient service and minimal bandwidth usage regardless of load.
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FreeNet History
 Freenet is an enhanced Open Source implementation of the
system described by Ian Clarke's 1999 paper "A distributed
decentralized information storage and retrieval system“.
 Work started on Freenet shortly after the publication of this
paper in July 1999 by Clarke and a small number of
volunteers.
 By March 2000 version 0.1 of Freenet was released.
 Since March 2000 Freenet has been extensively reported in
the press, primarily due to its implications for copyright rather
than for its wider aim, namely freedom of communication.
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Freenet Structure
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Review of P2P Architecture
 Napster – Hybrid P2P
 Gnutella – Pure P2P
 FreeNet – Purest P2P
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Future of P2P
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Future of P2P
IT Prospect From Gartner
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Future of P2P
 Next Generation of IT Architecture
Mainframe
Client/Server
P2P
 P2P Protocol Standard is required
 Killer Application of P2P is required
 Profit Model based on User’s Communities
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