1. P2P WeeSan Lee weesan@cs.ucr.eduweesan@cs.ucr.edu

2. What is a client-server model? GET rfc1855.txt Web Server Client 1Client 2 rfc1855.txt

3. What is a peer-to-peer model? Web Server Client 1Client 2 rfc1855.txt

4. What is a peer-to-peer model? Host 3 Host 1Host 2 rfc1855.txt GET rfc1855.txt rfc1855.txt GET rfc1855.txt

5. What is a peer-to-peer model? There is no server nor client, only peers In fact, each peer is both server and client

6. P2P Network An overlay network that employs P2P model For example  Napster  KaZaA  Gnutella  BitTorrent

7. P2P Network - Napster A centralized P2P network  Centralized index server Created by Shawn Fanning from Northeastern University in 1999 A centralized way to look for mp3 music instead of from IRCs or newsgroups Later sued by RIAA (Recording Industry Association of America) and shutdown in 2001

8. P2P Network - KaZaA A semi-centralized P2P network Created by Niklas Zennström and Janus Friis  Whom later founded Skypes in 2003 Like Napster, KaZaA had been sued by music record companies

9. P2P Network - Gnutella A pure, unstructured P2P network All peers act as equals  No centralized server Still need a way to bootstrap though Software  LimeWire Pros  No single point of failure Cons  Could be very slow Solution: Ultra Peers

10. P2P Network - BitTorrent A P2P file sharing communications protocol for large files such as movies, TV shows, etc Created by Bram Cohen in 2001 Software  ABC  Azureus  BitComet  BitLord  BitTorrent  Opera  μTorrent

11. P2P Network - BitTorrent Torrent file  A small file contains the information of the file or a group of files (also called torrent) one would like to share, and the trackers  Usually with.torrent extension Tracker  A computer that tells the downloaders where to download the files

12. P2P Network - BitTorrent Seeder  A peer that has completed copy of the torrent Leecher  A peer that does not have completed copy of the torrent Swarm  All peers sharing a torrent are called a swarm

13. P2P Network - BitTorrent Torrent Search Engines  Mininova  TorrentSpy  Isohunt

14. Beside File Sharing Bioinformatics  P2P networks are used to run large programs to find cure Academic Search Engine  Free and open search engine for scientific knowledge Education and Academic  Share academic content

15. Beside File Sharing (cont) Business  Content distribution Software TV shows Telecommunication  Skype

16. Attacks on P2P Network Poisoning  Provide different contents Polluting  Provide bad data

17. A Few Final Words Engaging P2P file sharing on UC campuses is prohibited From http://www.riaa.com/faq.phphttp://www.riaa.com/faq.php  “When you go online and download songs without permission, you are stealing.”  “Pay a little now or a lot more later.”  “Anyone – and everyone – engaged in music theft is at risk for a lawsuit.”

18. A Few Final Words (cont) From http://www.musicunited.org/2_thelaw.html http://www.musicunited.org/2_thelaw.html  Criminal penalties for first-time offenders can be as high as five years in prison and $250,000 in fines.  Civil penalties can run into many thousands of dollars in damages and legal fees. The minimum penalty is $750 per song.

19. References Internet Effectively  Ch 13 - The Internet’s Impact on Traditional Media Peer-to-peer  http://en.wikipedia.org/wiki/Peer-to-peer http://en.wikipedia.org/wiki/Peer-to-peer BitTorrent  http://en.wikipedia.org/wiki/BitTorrent RIAA FAQ  http://www.riaa.com/faq.php http://www.riaa.com/faq.php

20. Homework 9 Read “Is Someone Tracking P2P Users?” by A. Banerjee, M. Faloutsos and L. Bhuyan  http://www.cs.ucr.edu/~anirban/Anir- networking07.pdf http://www.cs.ucr.edu/~anirban/Anir- networking07.pdf  Best Paper Award at IFIP Networking 2007 Post your comments on Homework 9 Forum