1. PEER TO PEER (P2P) NETWORK By: Linda Rockson 11/28/06

2. Outline: Definition of Peer-to-Peer (P2P) P2P technologies LimeWire (Latest Technology) How LimeWire works Protocol survey Structured and Unstructured P2P Difference between P2P and server based The future of P2P References and Conclusion

3. Definition of P2P A peer-to-peer (P2P) network is one that relies primarily on the resources of the participants in the network rather than on a server (wikipedia)

4. P2P Technologies Napster Gnutella Freenet KaZaA Morpheus LimeWire BearShare

5. Napster

6. Napster (con’t) Brief History How Napster works: Central Server (stores location). Peers store files Is Napster a true P2P?

7. Gnutella

8. Gnutella (con’t) Brief History How Gnutella works (uses TTL) : No central server Equal peers - (clients + server roles) Gnutella - a true P2P Anonymosities

9. Gnutella (con’t)

10. LimeWire (Latest Technology) Fastest File Sharing Program Gnutella – based application. Open standard software running on an open protocol Allows file-sharing for.mp3,.jpg,.tiff, Written in Java. Runs on Windows, Mac, Linux, Sun

11. How LimeWire works

12. How LimeWire works (con’t) Node A1 is first connected to the network. Pings to Nodes (B and C) to find new nodes on the network. Pong message(node, IP, port No, No files shared) Sends a query for files shared by other nodes. Reply (file(s), size, link speed of the node) Downloads required file for play/use

13. Freenet Brief History How Freenet works No central server Equal peers - (clients + server roles) Inserting resources Search Termination Anonymous – secure network

14. Kazaa

15. Popular protocols Fastrack (latest) Morpheus / Bearshare / Gnutella Gnutella 2 Kazaa eDonkey DC++ (directConnect) Bittorent

16. FastTrack protocol Used by KaZaA and Morpheus Supernodes and nodes Scalable Routing Routing Replies Routing Problems Partial Decentralisation

17. P2P Protocols Problem Problem: Creates traffic (act server + client) Solution ET/BWMGR software "sniff out" protocols Controls or block traffic Completely disallows communication Finds protocols irrespective of port used (80)

18. Structured and Unstructured P2P Basis – nodes linkage in the network Unstructured: Easily constructed: copy existing links Searches by flooding queries Disadvantage (unresolved queries) Eg: Napster, Gnutella, KaZaA

19. Structured P2P Maintains a Distributed Hash Table (DHT) Peer responsibility Searches with hash function More efficient Egs: Chord, Tapestry, CAN, Tulip

20. Advantages of P2P over server based Inexpensive high scability Network growth increases resources No centralized systems – hence cheap 1 program on multiple machines at once Server: traffic, goes down, resources

21. Future of Peer-to-Peer Lack of scalability. Trust (resources) in the network Virus control It must be robust (logout leads to difficult download)

22. References users.edinboro.edu/dtucker www.google.com www.howstuffworks.com www.napster.com www.kazaa.com www.gnutella.com www.limewire.com

23. Questions / Conclusion ? ? ? ? ?