Peer-to-Peer network systems Distributed Data Processing Paulina Pasek

Content Introduction How does internet p2p work? History Advantages Disadvantages Legal controversy Networks and their applications Summary Sources

Whata is peer-to-peer (p2p)? 1.„(…) a type of network in which each work station has equivalent capabilities and responsibilities” source: webopedia.com 2."individual computers may share hard drives, CD-ROM drives, and other storage devices with the other computers on the network." Contrast with this, in a client/server set-up, "most of the computers (clients) tend to share resources from one main computer (the server). " source: p2p.inf.pl 3.Peer-to-peer is a communications model in which each party has the same capabilities and either party can initiate a communication session. Other models with which it might be contrasted include the client/server model and the master/slave model..." source: searchNetworking.techtarget.com

File sharing – the differences In FTP (File Transfer Protocol) and HTTP (HyperText Transfer Protocol) must be some server, someone have to buy it and take care of it. Easy to find operator if on server are illegal files If many people know about it could be a problem with downloading In p2p No servers (connecting directly to computer) Easy to upload something You don’t need money Nobody can permit the operator of the server cause there is no server No problems with download speed (because there is no server)

of data sharing Example of data sharing

How does internet p2p work? The user must first downlad and execute a peer-to-peer networking program. After launching the program, the user enters the IP address of another computer beloning to the network. Once the computer finds another network member on-line, it will connect to that user’s connection Users can choose how many member connections to seek at one time and determine which files they wish to share or password protect

History July, 1999: publication of Freenet protocol September, 1999: creation of Napster November, 1999: first release of Direct Connect client March 14, 2000: first release of Gnutella September 6, 2000: first release of eDonkey2000 March, 2001: introduction of the FastTrack protocol April, 2001: design of the BitTorrent protocol July, 2001: shutdown of Napster November 6, 2001: first release of GNUnet November, 2002: start of the Gnutella2 project

Advantages each user increases total capacity of the network low maintenance costs flexible structure (”liquid topology”) end of Internet asymmetry Almost free Fast dowlanding Very popular

Disadvantages Not so safe: viruses, spam, spyware downloaded files may be infected, contain unsolicited information, violate privacy Sometimes illegal copyrighted files within p2p networks

What should we be aware of? shared files as copies of copyrighted music, movies, programs, e-books, etc… MPAA (Motion Picture Association), RIAA (Recording Industry Association of America) – an example of organizations fighting with piracy small loophole…

What are we allowed to download? files with authors’ permission to download – (wallpapers, anime music videos) files without current copyrights – (e.g. old programs, lot of remixes) files with time-out copyrights – (classical music, old e-books)

Networks and their clients IRC IRC Napster Napster Gnutella Gnutella FastTrack FastTrack Freenet Freenet Direct Connect Direct Connect eDonkey eDonkey Skype Skype

IRC IRC (Internet Relay Chat) it’s not p2p network Have a conversations is for help channels in IRC net DCC (Direct Client-to-Client) The users use pseudonyms like nicname or short nick

Napster the first p2p network created by Shawn Fanning (1999) Napster users can’t only play the music back after downlading it but put it on their own CD. closed in 2001 (lost lawsuit), returned in 2003 as paid service Logo:

Gnutella Gnutella lets users share files from user machine to user machine without the use of a central directory In Gnutella don’t have a central server Files are changing between users You are connecting directly to host without any servers The first program was written by Justin Frankl and Tom Pepper Name of Gnutella is compound words GNU and Nutella Adwantages: biggest no. of clients no queue a lot of files avaliable Logo:

BitTorrent Written by San Francisco programmer Bram Cohen in 2002 BitTorrent is similar to KaZaA and other distributed swapping services users download from other users and do not use a centralized directory as in the original Napster service BitTorrent is also different than all of them because it makes every downloading user an uploading user Logo:

eDonkey p2p file sharing application developed by MetaMachine Like most file sharing networks, it is decentralized files are not stored on a central server but are exchanged directly between users based on the p2p principle. Advantages: lot of files very good queue biggest network Logo:

FastTrack P2p protocal used by the Kazaa file sharing programs In 2003 it was the most popular file sharing network The network had approximately 2.4 million concurrent users in 2003 the brainchild of Niklas Zennstrom, Janus Friis and Estonian programmers headed by Jaan Tallinn, the same team that later created Skype Most famous clients: iMesh*, Mammoth, Kazaa, Kazaa Lite, Diet Kazaa Advantages: good from technical point of view lot of take files Logo:

Direct Connet P2P file sharing application written by NeoModus today is the general type of application used in a Direct Connect network Direct connect clients connect to a central hub and can download files directly from one another Hubs feature a list of clients or users connected to them. Users can search for files and download them from other clients, as well as chat with other users. Logo:

Skype It was created by Niklas Zennström, Janus Friis, and a team of software developers based in Tallinn, Estonia Instant messaging based on p2p Conferences Connect directly to user Possibility exchange files Chat Logo:

How does it look?

Summary Very useful, very flexible Very popular P2P as alternative to FTP and HTTP Fast downlading Not so save Almost free

Sources

Thank you For your attention