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PEER TO PEER (P2P) NETWORK. By: Linda Rockson 11/28/06. 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
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PEER TO PEER (P2P) NETWORK By: Linda Rockson 11/28/06
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
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)
P2P Technologies • Napster • Gnutella • Freenet • KaZaA • Morpheus • LimeWire • BearShare
Napster (con’t) • Brief History • How Napster works: • Central Server (stores location). • Peers store files • Is Napster a true P2P?
Gnutella (con’t) • Brief History • How Gnutella works (uses TTL) : • No central server • Equal peers - (clients + server roles) • Gnutella - a true P2P • Anonymosities
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
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
Freenet • Brief History • How Freenet works • No central server • Equal peers - (clients + server roles) • Inserting resources • Search Termination • Anonymous – secure network
Popular protocols • Fastrack (latest) • Morpheus / Bearshare / Gnutella • Gnutella 2 • Kazaa • eDonkey • DC++ (directConnect) • Bittorent
FastTrack protocol • Used by KaZaA and Morpheus • Supernodes and nodes • Scalable • Routing • Routing Replies • Routing Problems • Partial Decentralisation
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)
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
Structured P2P • Maintains a Distributed Hash Table (DHT) • Peer responsibility • Searches with hash function • More efficient • Egs: Chord, Tapestry, CAN, Tulip
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
Future of Peer-to-Peer • Lack of scalability. • Trust (resources) in the network • Virus control • It must be robust (logout leads to difficult download)
References • users.edinboro.edu/dtucker • www.google.com • www.howstuffworks.com • www.napster.com • www.kazaa.com • www.gnutella.com • www.limewire.com
Questions / Conclusion ? ? ? ? ? ? ?