For other uses of the term see Peer-to-peer (disambiguation)

For peer-to-peer networks used for file sharing see File sharing

A peer to peer (or "P2P") computer network uses diverse connectivity between participants in a network and the cumulative bandwidth of network participants rather than conventional centralized resources where a relatively low number of servers provide the core value to a service or application. A computer network is a group of interconnected Computers. Networks may be classified according to a wide variety of characteristics In Computer networking and Computer science, digital bandwidth or just bandwidth is the capacity for a given system to transfer data over a connection A server is a Computer dedicated to providing one or more services over a computer network typically through a request-response routine P2P networks are typically used for connecting nodes via largely ad hoc connections. The term node as used in the field of telecommunications refers to an active electronic device that is capable of sending receiving or forwarding information over a communications channel Such networks are useful for many purposes. Sharing content files (see file sharing) containing audio, video, data or anything in digital format is very common, and realtime data, such as telephony traffic, is also passed using P2P technology. See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Voice-over-Internet protocol ( VoIP, vɔɪp is a protocol optimized for the transmission of voice through the Internet

A pure P2P network does not have the notion of clients or servers, but only equal peer nodes that simultaneously function as both "clients" and "servers" to the other nodes on the network. A client is an application or system that accesses a remote service on another Computer system, known as a server, by way of a Network. A node ( Latin nodus, ‘knot’ is a critical element of any Computer network. This model of network arrangement differs from the client-server model where communication is usually to and from a central server. The client-server Software architecture model distinguishes client systems from server systems which communicate over a Computer network A typical example of a file transfer that is not P2P is an FTP server where the client and server programs are quite distinct, the clients initiate the download/uploads, and the servers react to and satisfy these requests.

The earliest P2P network in widespread use was the Usenet news server system, in which peers communicated with one another to propagate Usenet news articles over the entire Usenet network. Usenet, a Portmanteau of "user" and "network" is a world-wide distributed Internet discussion system A news server is a set of Computer software used to handle Usenet articles Usenet, a Portmanteau of "user" and "network" is a world-wide distributed Internet discussion system Particularly in the earlier days of Usenet, UUCP was used to extend even beyond the Internet. UUCP is an Abbreviation for Unix to Unix CoPy. The term generally refers to a suite of Computer programs and protocols allowing remote execution The Internet is a global system of interconnected Computer networks However, the news server system also acted in a client-server form when individual users accessed a local news server to read and post articles. The same consideration applies to SMTP email in the sense that the core email relaying network of Mail transfer agents is a P2P network while the periphery of Mail user agents and their direct connections is client server. Simple Mail Transfer Protocol ( SMTP) is a De facto standard for electronic mail (e-mail transmissions across the Internet. A mail transfer agent (MTA (also called a mail transport agent, message transfer agent, or smtpd (short for SMTP daemon) is a An e-mail client, aka Mail User Agent (MUA aka e-mail reader is a frontend Computer program used to manage E-mail.

Some networks and channels such as Napster, OpenNAP and IRC server channels use a client-server structure for some tasks (e. Napster was an online music file sharing service created by Shawn Fanning while he was attending Northeastern University in Boston and operating OpenNap is a discontinued peer-to-peer service server It was created as an Open source Napster server extending the Napster protocol to allow sharing of any A serving channel (sometimes called a depot channel) is a Slang term for a File sharing channel found on an IRC network g. searching) and a P2P structure for others. Networks such as Gnutella or Freenet use a P2P structure for all purposes, and are sometimes referred to as true P2P networks, although Gnutella is greatly facilitated by directory servers that inform peers of the network addresses of other peers. Gnutella (nʊˈtɛlə with a silent g, or alternatively /gnʊˈtɛlə/ is a File sharing network Freenet is a decentralized Censorship -resistant Distributed data store originally designed by Ian Clarke.

P2P architecture embodies one of the key technical concepts of the Internet, described in the first Internet Request for Comments, RFC 1, "Host Software" dated 7 April 1969. In Computer network Engineering, a Request for Comments (RFC is a Memorandum published by the Internet Engineering Task Force (IETF describing Events 529 - First draft of Corpus Juris Civilis (a fundamental work in Jurisprudence) is issued by Eastern Roman Emperor Year 1969 ( MCMLXIX) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. More recently, the concept has achieved recognition in the general public in the context of the absence of central indexing servers in architectures used for exchanging multimedia files. A server is a Computer dedicated to providing one or more services over a computer network typically through a request-response routine

The concept of P2P is increasingly evolving to an expanded usage as the relational dynamic active in distributed networks, i. e. not just computer to computer, but human to human. Yochai Benkler has coined the term "commons-based peer production" to denote collaborative projects such as free software. Yochai Benkler is Jack N and Lillian R Berkman Professor for Entrepreneurial Legal Studies at Harvard Law School and the author of The Wealth of Networks Associated with peer production are the concept of peer governance (referring to the manner in which peer production projects are managed) and peer property (referring to the new type of licenses which recognize individual authorship but not exclusive property rights, such as the GNU General Public License and the Creative Commons licenses). Creative Commons (CC is a Non-profit organization devoted to expanding the range of creative works available for others to build upon legally and to share

Contents 1 Classifications of P2P networks 2 Advantages of P2P networks 3 Unstructured and structured P2P networks 4 Legal controversy 5 Computer science perspective 6 Application of P2P network outside computer science 7 Security 7.1 Anonymity 7.2 Encryption 8 Networks, protocols and applications 8.1 Other types of peer-to-peer applications 8.2 Networks and protocols 8.3 Multi-network applications 9 History 10 See also 11 References 12 External links

Classifications of P2P networks

P2P networks can be classified by what they can be used for:

• file sharing
• telephony
• media streaming (audio, video)
• discussion forums

Other classification of P2P networks is according to their degree of centralization.

In 'pure' P2P networks:

• Peers act as equals, merging the roles of clients and server
• There is no central server managing the network
• There is no central router

Some examples of pure P2P application layer networks designed for file sharing are Gnutella and Freenet. The Application Layer is the seventh level of the seven-layer OSI model, and the top layer of the TCP/IP model See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Gnutella (nʊˈtɛlə with a silent g, or alternatively /gnʊˈtɛlə/ is a File sharing network Freenet is a decentralized Censorship -resistant Distributed data store originally designed by Ian Clarke.

There also exist countless hybrid P2P systems:

• Has a central server that keeps information on peers and responds to requests for that information.
• Peers are responsible for hosting available resources (as the central server does not have them), for letting the central server know what resources they want to share, and for making its shareable resources available to peers that request it.
• Route terminals are used as addresses, which are referenced by a set of indices to obtain an absolute address.

e. g.

• Centralized P2P network such as Napster
• Decentralized P2P network such as KaZaA
• Structured P2P network such as CAN
• Unstructured P2P network such as Gnutella
• Hybrid P2P network (Centralized and Decentralized) such as JXTA (an open source P2P protocol specification)

Advantages of P2P networks

An important goal in P2P networks is that all clients provide resources, including bandwidth, storage space, and computing power. Napster was an online music file sharing service created by Shawn Fanning while he was attending Northeastern University in Boston and operating Kazaa Media Desktop (once capitalized as " KaZaA " but now usually written " Kazaa " is a Peer-to-peer File sharing application The Content Addressable Network ( CAN) is a distributed decentralized P2P infrastructure that provides Hash table functionality on an Internet Gnutella (nʊˈtɛlə with a silent g, or alternatively /gnʊˈtɛlə/ is a File sharing network JXTA ( Juxtapose) is an Open source Peer-to-peer protocol specification begun by Sun Microsystems in 2001 Thus, as nodes arrive and demand on the system increases, the total capacity of the system also increases. This is not true of a client-server architecture with a fixed set of servers, in which adding more clients could mean slower data transfer for all users.

The distributed nature of P2P networks also increases robustness in case of failures by replicating data over multiple peers, and -- in pure P2P systems -- by enabling peers to find the data without relying on a centralized index server. In the latter case, there is no single point of failure in the system. Reliability engineering is an Engineering field that deals with the study of Reliability: the ability of a System or component to perform its required ^[1]

Unstructured and structured P2P networks

The P2P overlay network consists of all the participating peers as network nodes. An overlay network is a Computer network which is built on top of another network There are links between any two nodes that know each other: i. e. if a participating peer knows the location of another peer in the P2P network, then there is a directed edge from the former node to the latter in the overlay network. Based on how the nodes in the overlay network are linked to each other, we can classify the P2P networks as unstructured or structured.

An unstructured P2P network is formed when the overlay links are established arbitrarily. Such networks can be easily constructed as a new peer that wants to join the network can copy existing links of another node and then form its own links over time. In an unstructured P2P network, if a peer wants to find a desired piece of data in the network, the query has to be flooded through the network to find as many peers as possible that share the data. The main disadvantage with such networks is that the queries may not always be resolved. Popular content is likely to be available at several peers and any peer searching for it is likely to find the same thing. But if a peer is looking for rare data shared by only a few other peers, then it is highly unlikely that search will be successful. Since there is no correlation between a peer and the content managed by it, there is no guarantee that flooding will find a peer that has the desired data. Flooding also causes a high amount of signaling traffic in the network and hence such networks typically have very poor search efficiency. Most of the popular P2P networks such as Gnutella and FastTrack are unstructured. Gnutella (nʊˈtɛlə with a silent g, or alternatively /gnʊˈtɛlə/ is a File sharing network FastTrack is a Peer-to-peer (P2P protocol, used by the Kazaa (and variants Grokster and IMesh) File sharing programs

Structured P2P network employ a globally consistent protocol to ensure that any node can efficiently route a search to some peer that has the desired file, even if the file is extremely rare. Such a guarantee necessitates a more structured pattern of overlay links. By far the most common type of structured P2P network is the distributed hash table (DHT), in which a variant of consistent hashing is used to assign ownership of each file to a particular peer, in a way analogous to a traditional hash table's assignment of each key to a particular array slot. Distributed hash tables ( DHTs) are a class of decentralized distributed systems that provide a lookup service similar to a Hash table: ( name, Consistent hashing is a scheme that provides Hash table functionality in a way that the addition or removal of one slot does not significantly change the mapping of keys to slots In Computer science, a hash table, or a hash map, is a Data structure that associates keys with values. Some well known DHTs are Chord, Pastry, Tapestry, CAN, and Tulip. Chord is one of the original Distributed hash table protocols This article describes the Pastry Distributed Hash Table For the food see Pastry. Tapestry is a Distributed hash table which provides a decentralized object location Routing, and Multicasting infrastructure for distributed applications The Content Addressable Network ( CAN) is a distributed decentralized P2P infrastructure that provides Hash table functionality on an Internet Tulip is a distributed decentralized P2P network intended for routing searching and publish-lookup information sharing Not a DHT-approach but a structured P2P network is HyperCuP.

Legal controversy

See also: File sharing and the law

In Sony Corp. See also File sharing The legal issues in File sharing involve violation of Copyright laws as digital copies of copy-written materials are transferred between v. Universal Studios, 464 U. S. 417 (1984), the Supreme Court found that Sony's new product, the Betamax, did not subject Sony to secondary copyright liability because it was capable of substantial non-infringing uses. Decades later, this case became the jumping-off point for all peer-to-peer copyright infringement litigation.

The first peer-to-peer case was A&M Records v. Napster, 239 F. 3d 1004 (9th Cir. 2001). In the Napster case, the 9th Circuit considered whether Napster was liable as a secondary infringer. First, the court considered whether Napster was contributorily liable for copyright infringement. To be found contributorily liable, Napster must have engaged in "personal conduct that encourages or assists the infringement. " ^[2] The court found that Napster was contributorily liable for the copyright infringement of its end-users because it "knowingly encourages and assists the infringement of plaintiffs' copyrights. "^[3] The court goes on to analyze whether Napster was vicariously liable for copyright infringement. The standard applied by the court is whether Napster "has the right and ability to supervise the infringing activity and also has a direct financial interest in such activities. "^[4] The court found that Napster did receive a financial benefit, and had the right and ability to supervise the activity, meaning that the plaintiffs demonstrated a likelihood of success on the merits of their claim of vicarious infringement. ^[5] The court denied all of Napster's defenses, including its claim of fair use.

The next major peer-to-peer case was MGM v. Grokster, 514 U. S. 913 (2005). In this case, the Supreme Court found that even if Grokster was capable of substantial non-infringing uses, which the Sony Court found was enough to relieve one of secondary copyright liability, Grokster was still secondarily liable because it induced its users to infringe. ^[6]

Computer science perspective

Technically, a completely pure P2P application must implement only peering protocols that do not recognize the concepts of "server" and "client". Such pure peer applications and networks are rare. Most networks and applications described as P2P actually contain or rely on some non-peer elements, such as DNS. The Domain Name System (DNS is a hierarchical naming system for computers services or any resource participating in the Internet. Also, real world applications often use multiple protocols and act as client, server, and peer simultaneously, or over time. Completely decentralized networks of peers have been in use for many years: two examples are Usenet (1979) and FidoNet (1984). Usenet, a Portmanteau of "user" and "network" is a world-wide distributed Internet discussion system

Many P2P systems use stronger peers (super-peers, super-nodes) as servers and client-peers are connected in a star-like fashion to a single super-peer.

Sun added classes to the Java technology to speed the development of P2P applications quickly in the late 1990s so that developers could build decentralized real time chat applets and applications before Instant Messaging networks were popular. This effort is now being continued with the JXTA project. JXTA ( Juxtapose) is an Open source Peer-to-peer protocol specification begun by Sun Microsystems in 2001

P2P systems and applications have attracted a great deal of attention from computer science research; some prominent research projects include the Chord project, the PAST storage utility, the P-Grid, a self-organized and emerging overlay network and the CoopNet content distribution system (see below for external links related to these projects). Chord is one of the original Distributed hash table protocols PAST is a large-scale distributed persistent storage system based on the Pastry Peer-to-peer overlay network P-Grid is a self-organizing structured Peer-to-peer system which can accommodate arbitrary key distributions (and hence support lexicographic key ordering and range queries CoopNet (Cooperative Networking, a system for off-loading serving to Peers who have recently downloaded content is described in the paper “The Case for Cooperative

Application of P2P network outside computer science

• Bioinformatics: P2P networks have also begun to attract attention from scientists in other disciplines, especially those that deal with large datasets such as bioinformatics. Bioinformatics is the application of information technology to the field of molecular biology P2P networks can be used to run large programs designed to carry out tests to identify drug candidates. The first such program was begun in 2001 the Centre for Computational Drug Discovery at Oxford University in cooperation with the National Foundation for Cancer Research. The University of Oxford (informally "Oxford University" or simply "Oxford" located in the city of Oxford, Oxfordshire, England is the There are now several similar programs running under the auspices of the United Devices Cancer Research Project. gridorg is a website and online community established in 2001 that focuses on Cluster computing and Grid computing software for users On a smaller scale, a self-administered program for computational biologists to run and compare various bioinformatics software is available from Chinook. Tranche is an open-source set of software tools for setting up and administrating a decentralized network. It was developed to solve the bioinformatics data sharing problem in a secure and scalable fashion.

• Academic Search engine: The sciencenet P2P search engine provides a free and open search engine for scientific knowledge. "Sciencenet" is an experimental search engine at KIT ( Karlsruhe Institute of Technology - Liebel-Lab for scientific knowledge sciencenet is based on yacy technology. "Sciencenet" is an experimental search engine at KIT ( Karlsruhe Institute of Technology - Liebel-Lab for scientific knowledge YaCy (read "ya see" is a free distributed Search engine, built on principles of Peer-to-peer (P2P networks Universities / research institutes can download the free java software and contribute with their own peer(s) to the global network. Liebel-Lab @ Karlsruhe institute of technology KIT.

• Education and Academia: Due to the fast distribution and large storage space features, many organizations are trying to apply P2P networks for educational and academic purposes. For instance, Pennsylvania State University, MIT and Simon Fraser University are carrying on a project called LionShare designed for facilitating file sharing among educational institutions globally.

• Military: The U. S. Department of Defense has already started research on P2P networks as part of its modern network warfare strategy. In November, 2001, Colonel Robert Wardell from the Pentagon told a group of P2P software engineers at a tech conference in Washington, DC: "You have to empower the fringes if you are going to. . . be able to make decisions faster than the bad guy". ^[7] Wardell indicated he was looking for P2P experts to join his engineering effort. In May, 2003 Dr. Tether. Director of Defense Advanced Research Project Agency testified that U. S. Military is using P2P networks. Due to security reasons, details are kept classified.

• Business: P2P networks have already been used in business areas, but it is still in the beginning stages. Currently, Kato et al’s studies indicate over 200 companies with approximately $400 million USD are investing in P2P network. Besides File Sharing, companies are also interested in Distributing Computing, Content Distribution, e-marketplace, Distributed Search engines, Groupware and Office Automation via P2P networks. There are several reasons why companies prefer P2P sometimes, such as: Real-time collaboration--a server cannot scale well with increasing volume of content; a process which requires strong computing power; a process which needs high-speed communications, etc. At the same time, P2P is not fully used as it still faces a lot of security issues.

• TV: Quite a few applications available to delivery TV content over a P2P network (P2PTV)

• Telecommunication: Nowadays, people are not just satisfied with “can hear a person from another side of the earth”, instead, the demands of clearer voice in real-time are increasing globally. The term P2PTV refers to Peer-to-peer (P2P Software applications designed to redistribute video streams in real time on a P2P network Just like the TV network, there are already cables in place, and it's not very likely for companies to change all the cables. Many of them turn to use the internet, more specifically P2P networks. For instance, Skype, one of the most widely used internet phone applications is using P2P technology. Skype (skaɪp is Software that allows users to make telephone calls over the Internet. Furthermore, many research organizations are trying to apply P2P networks to cellular networks.

Security

Anonymity

Main article: Anonymous P2P

Some P2P protocols (such as Freenet) attempt to hide the identity of network users by passing all traffic through intermediate nodes. An anonymous P2P computer network is a particular type of Peer-to-peer network in which the users are anonymous or pseudonymous by default Freenet is a decentralized Censorship -resistant Distributed data store originally designed by Ian Clarke.

Encryption

Some P2P networks encrypt the traffic flows between peers.

This may help to:

• make it harder for an ISP to detect that peer-to-peer technology is being used (as some artificially limit bandwidth)
• hide the contents of the file from eavesdroppers
• impede efforts towards law enforcement or censorship of certain kinds of material
• authenticate users and prevent 'man in the middle' attacks on protocols
• aid in maintaining anonymity

Networks, protocols and applications

Other types of peer-to-peer applications

• File sharing (using application layer protocols as BitTorrent)
• VoIP (using application layer protocols as SIP)
• Streaming media
• Instant messaging
• Software publication and distribution
• Media publication and distribution (radio, video)

Networks and protocols

Network or Protocol	Use	Applications
Ares	File sharing	Ares Galaxy, Warez P2P
BitTorrent	File sharing/Software distribution/Media distribution	ABC, AllPeers, Azureus, BitComet, BitLord, BitTornado, BitTorrent, Burst!, Deluge, FlashGet, G3 Torrent, Halite, KTorrent, LimeWire, MLDonkey, Opera, QTorrent, rTorrent, TorrentFlux, Transmission, Tribler, µTorrent, Thunder, Shareaza
CSpace	File sharing, text chat, remote desktop	a peer-to-peer based communications system
Direct Connect	File sharing	DC++, NeoModus Direct Connect, SababaDC, BCDC++, ApexDC++, StrongDC++
Domain Name System	Internet information retrieval	See Comparison of DNS server software
eDonkey	File sharing	aMule, eDonkey2000 (discontinued), eMule, eMule Plus, FlashGet, iMesh, Jubster, lMule, MLDonkey, Morpheus, Pruna, xMule, Shareaza
FastTrack	File sharing	giFT, Grokster, iMesh (and its variants stripped of adware including iMesh Light), Kazaa (and its variants stripped of adware such as Kazaa Lite), KCeasy, Mammoth, MLDonkey, Poisoned
Freenet	Distributed data store	Entropy (on its own network), Freenet
G3	File sharing	FilesWire (Web based P2P), DeskWire
GNUnet	File sharing, chat	GNUnet, (GNUnet-gtk)
Gnutella	File sharing	Acquisition, BearShare, Cabos, FrostWire, Gnucleus, Grokster, gtk-gnutella, iMesh, Kiwi Alpha, LimeWire, MLDonkey, Morpheus, Poisoned, Swapper, XoloX, Shareaza
Gnutella2	File sharing	Adagio, Gnucleus, iMesh, Kiwi Alpha, MLDonkey, Morpheus, TrustyFiles, Shareaza
Kad Network	File sharing	aMule, eMule, MLDonkey
JXTA	Peer applications	Collanos Workplace (Teamwork software), Sixearch
Krawler	Social network	Krawler[x]
MANOLITO/MP2P	File sharing	Blubster, Piolet
MFPnet	File sharing	amiciPhone (no longer available)
Napster	File sharing	Napigator, Napster
NeoEdge	File sharing	MostFun Game Player, NeoARM game delivery
OpenNap	File sharing	WinMX, Utatane, XNap, Napster
P2PTV	Video stream or file sharing	TVUPlayer, Joost, CoolStreaming, Cybersky-TV, TVants, PPLive, Kontiki, LiveStation
PDTP	Streaming media or file sharing	PDTP
Peercasting	Multicasting streams	PeerCast, IceShare, FreeCast, Rawflow
Pichat	Chat, Collaboration	a peer-to-peer chat platform
Usenet	Distributed discussion	See list of news clients
WPNP	File sharing	WinMX
Windows Peer-to-Peer	Distributed peer application development, collaboration [8]	Shipped with Advanced Networking Pack for Windows XP [9], Windows XP SP2, Windows Vista. See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a BitTorrent is a Peer-to-peer File sharing protocol used to distribute large amounts of Data. Voice-over-Internet protocol ( VoIP, vɔɪp is a protocol optimized for the transmission of voice through the Internet The Session Initiation Protocol ( SIP) is a signalling protocol widely used for setting up and tearing down Multimedia Communication sessions Streaming multimedia is Multimedia that is constantly received by and normally presented to an end-user while it is being delivered by a streaming provider (the Ares Galaxy is an open source Peer-to-peer File sharing application that uses its own decentralized supernode/leaf network See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Ares Galaxy is an open source Peer-to-peer File sharing application that uses its own decentralized supernode/leaf network Warez P2P is a proprietary P2P Filesharing service released in January 2004 that uses the Ares network, and offers a service similar to that of BitTorrent is a Peer-to-peer File sharing protocol used to distribute large amounts of Data. See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a ABC is a Free software, open source BitTorrent client based on BitTornado. AllPeers was a Free software extension for the Mozilla Firefox browser introduced in 2006 BitComet (originally named SimpleBT client from versions 011 to 0 BitLord is a BitTorrent client written in C++ for Microsoft Windows. BitTornado is a BitTorrent client. It is developed by John Hoffman who also created its predecessor Shadow's Experimental Client. BitTorrent is a Peer-to-peer program developed by Bram Cohen and BitTorrent Inc Burst! is a client for the BitTorrent protocol Burst! uses a modified version of the original python client as the back-end and replaces the front-end with a Deluge is a BitTorrent client, created using Python and GTK+ (through PyGTK) FlashGet (formerly JetCar, from the literal translation of the Chinese phrase zh-cn 快车) is a Freeware Download manager for Microsoft G3 Torrent is an Open source ( MIT License) BitTorrent client Halite is an Open Source BitTorrent client written by Irishman Eóin O'Callaghan in C++ based on Libtorrent library from Rasterbar Software KTorrent is a BitTorrent client written in C++ for KDE using the Qt user interface toolkit MLDonkey is an Open source, Free software multi-network Peer-to-peer application Opera is a Web browser and Internet suite developed by the Opera Software company QTorrent is a graphical BitTorrent client based on PyQt. It is not to be confused with TorrentQ which is actually a spyware/malware ridden torrent client not rTorrent is a Text-based Ncurses BitTorrent client written in C++, based on the libTorrent libraries for UNIX (which TorrentFlux is a free and Open source multi-user GUI for BitTornado. Transmission is a free lightweight BitTorrent client which features a simple interface on top of a Cross-platform back-end Tribler is a file sharing client for Internet TV. Specifically Tribler is an Open source Peer-to-Peer client with various features for watching Thunder is the sound made by Lightning. Depending on the nature of the lightning and distance of the listener it can range from a sharp Shareaza is a Peer-to-peer file sharing client which supports the Gnutella, Gnutella2, EDonkey Network, BitTorrent, FTP See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Direct connect is a Peer-to-peer file-sharing protocol. Direct connect clients connect to a central hub and can download files directly from See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a DC++ is a free and open-source, Peer-to-peer file-sharing client that can be used to connect to the Direct Connect network NeoModus Direct Connect is a file-sharing client for Windows and Mac users that provides file-sharing capabilities for any type of file within a hub-centric DC++ is a free and open-source, Peer-to-peer file-sharing client that can be used to connect to the Direct Connect network DC++ is a free and open-source, Peer-to-peer file-sharing client that can be used to connect to the Direct Connect network DC++ is a free and open-source, Peer-to-peer file-sharing client that can be used to connect to the Direct Connect network DC++ is a free and open-source, Peer-to-peer file-sharing client that can be used to connect to the Direct Connect network The Domain Name System (DNS is a hierarchical naming system for computers services or any resource participating in the Internet. The Internet is a global system of interconnected Computer networks This article is a comparison of DNS server software, comparing the features platform support and packaging of independent implementations of DNS. The eDonkey network (also known as the eDonkey2000 network or eD2k) is a decentralized mostly server-based Peer-to-peer File sharing network See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a aMule is a free Peer-to-peer file sharing application that works with the EDonkey network and the Kad Network, offering similar features eDonkey2000 (nicknamed "ed2k" was a Peer-to-peer File sharing application developed by MetaMachine using the Multisource File Transfer Protocol eMule is a free Peer-to-peer file sharing application for Microsoft Windows. eMule Plus is an Open source EMule P2P compatible client created to improve its abilities and features in both work efficiency and GUI. FlashGet (formerly JetCar, from the literal translation of the Chinese phrase zh-cn 快车) is a Freeware Download manager for Microsoft iMesh is a File sharing and Online social network, available to download in 9 languages and uses a proprietary centralized P2P protocol operating on ports Jubster is a Windows -based Peer-to-peer client which supports the Gnutella, Gnutella2, EDonkey Network, FastTrack, and lMule (meaning Linux Mule was an early attempt to bring an EMule -like client to Linux started in January 2003 by Timo Kujala who ported MLDonkey is an Open source, Free software multi-network Peer-to-peer application Morpheus was a File sharing and searching peer to peer client for Microsoft Windows, developed and distributed by the company StreamCast, that Pruna is a city located in the province of Seville, Spain. According to the 2005 Census ( INE) the city has a population of 3060 xMule — the X11 Mule — is a client for the eDonkey Peer-to-peer File sharing network intended to bring it to virtually all the major Shareaza is a Peer-to-peer file sharing client which supports the Gnutella, Gnutella2, EDonkey Network, BitTorrent, FTP FastTrack is a Peer-to-peer (P2P protocol, used by the Kazaa (and variants Grokster and IMesh) File sharing programs See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a giFT Internet File Transfer ( giFT) is a computer software daemon that allows several File sharing protocols to be used with a simple client having a Grokster Ltd was a privately owned software company based in Nevis, West Indies that created the Grokster P2P file-sharing client in 2001 that utilized iMesh is a File sharing and Online social network, available to download in 9 languages and uses a proprietary centralized P2P protocol operating on ports Adware or advertising-supported software is any software package which automatically plays displays or downloads advertisements iMesh is a File sharing and Online social network, available to download in 9 languages and uses a proprietary centralized P2P protocol operating on ports Kazaa Media Desktop (once capitalized as " KaZaA " but now usually written " Kazaa " is a Peer-to-peer File sharing application Kazaa Lite is a Peer-to-peer file-sharing Computer program. The service is an unauthorized modification of the Kazaa Media Desktop (KMD application KCeasy is a Windows Peer-to-peer Filesharing application which uses GiFT as its 'back-end' foundation A mammoth is any Species of the Extinct Genus Mammuthus. These Proboscideans are members of the elephant family and MLDonkey is an Open source, Free software multi-network Peer-to-peer application Poisoned is a free Peer-to-peer File sharing client for Mac OS X, whose name is an allusion to the German word Gift Freenet is a decentralized Censorship -resistant Distributed data store originally designed by Ian Clarke. A distributed data store is a network in which a user stores his or her information on a number of peer network nodes. Entropy is a decentralized Peer-to-peer communication network designed to be resistant to Censorship, much like Freenet See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a GNUnet is a Free software framework for decentralized, Peer-to-peer networking. See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Gnutella (nʊˈtɛlə with a silent g, or alternatively /gnʊˈtɛlə/ is a File sharing network See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Acquisition is a Gnutella -based Peer-to-peer and BitTorrent client for Mac OS X. Cabos is a free Gnutella File sharing program It is based on LimeWire 's Source code, and has a similar feel in terms of interface FrostWire is a Peer-to-peer File sharing program for the Gnutella and BitTorrent protocols Gnucleus is a Gnutella and Gnutella2 client for Microsoft Windows, released under the GNU General Public License. Grokster Ltd was a privately owned software company based in Nevis, West Indies that created the Grokster P2P file-sharing client in 2001 that utilized gtk-gnutella is a Peer-to-peer file sharing application for Unix-like computer Operating systems which runs on the Gnutella network iMesh is a File sharing and Online social network, available to download in 9 languages and uses a proprietary centralized P2P protocol operating on ports Kiwi Alpha is a File sharing Peer-to-peer file sharing application that connects to the Gnutella and Gnutella2 networks by use of GnucDNA MLDonkey is an Open source, Free software multi-network Peer-to-peer application Morpheus was a File sharing and searching peer to peer client for Microsoft Windows, developed and distributed by the company StreamCast, that Poisoned is a free Peer-to-peer File sharing client for Mac OS X, whose name is an allusion to the German word Gift This is a list of fictional experiments from the Disney animated Lilo & Stitch franchise most of them making their first appearances in Lilo & Many projects have attempted to use the Gnutella network since its introduction in early 2000 Shareaza is a Peer-to-peer file sharing client which supports the Gnutella, Gnutella2, EDonkey Network, BitTorrent, FTP Gnutella2 ( G2) is a Peer-to-peer protocol developed mainly by Michael Stokes and released 2002. See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Adagio is a server -only Computer program for the Peer-to-peer Gnutella2 network. Gnucleus is a Gnutella and Gnutella2 client for Microsoft Windows, released under the GNU General Public License. iMesh is a File sharing and Online social network, available to download in 9 languages and uses a proprietary centralized P2P protocol operating on ports Kiwi Alpha is a File sharing Peer-to-peer file sharing application that connects to the Gnutella and Gnutella2 networks by use of GnucDNA MLDonkey is an Open source, Free software multi-network Peer-to-peer application Morpheus was a File sharing and searching peer to peer client for Microsoft Windows, developed and distributed by the company StreamCast, that TrustyFiles is a Closed source Microsoft Windows -based Peer-to-peer client which connects to the Gnutella, Gnutella2, FastTrack Shareaza is a Peer-to-peer file sharing client which supports the Gnutella, Gnutella2, EDonkey Network, BitTorrent, FTP The Kad network is a Peer-to-peer (P2P network which implements the Kademlia P2P overlay protocol See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a aMule is a free Peer-to-peer file sharing application that works with the EDonkey network and the Kad Network, offering similar features eMule is a free Peer-to-peer file sharing application for Microsoft Windows. MLDonkey is an Open source, Free software multi-network Peer-to-peer application JXTA ( Juxtapose) is an Open source Peer-to-peer protocol specification begun by Sun Microsystems in 2001 Collanos Workplace is a proprietary teamwork software. Installed on each team member’s computer it builds a team environment and transparent knowledge Collaborative software (also referred to as groupware or workgroup support systems) is software designed to help people involved in a common task achieve their Krawler Networks is a San Francisco based information technology company founded in 2005 MANOLITO or MP2P is the internal protocol name for the proprietary Peer-to-peer File sharing network developed by Pablo Soto, first used by See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Blubster is a music search download play and burn software client using the MANOLITO Peer-to-peer File sharing protocol French for Ice axe. Piolet is a MANOLITO Servent developed by Pablo Soto. See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Amicima Inc is a software company headquartered in Santa Cruz California, United States, developing new network protocols for Client-server and Napster was an online music file sharing service created by Shawn Fanning while he was attending Northeastern University in Boston and operating See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a Napster was an online music file sharing service created by Shawn Fanning while he was attending Northeastern University in Boston and operating Napster was an online music file sharing service created by Shawn Fanning while he was attending Northeastern University in Boston and operating NeoEdge Networks is a Silicon Valley based in-game advertising company that enables casual game publishers and developers to deliver Internet advertising as part of See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a OpenNap is a discontinued peer-to-peer service server It was created as an Open source Napster server extending the Napster protocol to allow sharing of any See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a WinMX is a Freeware Peer-to-peer File sharing program authored by Frontcode Technologies that runs on Microsoft Windows operating systems Utatane is the first album from the Japanese duo RYTHEM, released in 2004 XNap is a free Peer-to-peer client licensed under the GNU General Public License. Napster was an online music file sharing service created by Shawn Fanning while he was attending Northeastern University in Boston and operating The term P2PTV refers to Peer-to-peer (P2P Software applications designed to redistribute video streams in real time on a P2P network See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a TVU Networks Corporation is an Internet company that operates an Internet television broadcasting network that uses P2PTV technology to offer its broadcasters global reach and Joost ( like "juiced" is a system for distributing recorded TV shows and other forms of video over the Web using peer-to-peer TV technology, created by Niklas CoolStreaming is a P2PTV ( Peer-to-peer Television) technology that enables users to share television content with each other over the Internet Cybersky-TV is a free Software application for sharing Television signals using a P2PTV (Peer-To-Peer Television technology TVants is a P2PTV application written and designed by Zhejiang University. PPLive is a peer-to-peer streaming video network created in Huazhong University of Science and Technology, People's Republic of China. Kontiki is a peer-assisted content delivery technology company founded in November of 2000 Livestation is a platform for distributing live television and radio broadcasts over a Peer-to-peer data network The Peer Distributed Transfer Protocol is an Internet File transfer Protocol for distributing files from a central server across a Peer-to-peer Streaming multimedia is Multimedia that is constantly received by and normally presented to an end-user while it is being delivered by a streaming provider (the See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a The Peer Distributed Transfer Protocol is an Internet File transfer Protocol for distributing files from a central server across a Peer-to-peer Peercasting is a method of Multicasting streams, usually audio and/or video to the Internet via Peer-to-peer technology PeerCast is an Open source Streaming media multicast tool PeerCast uses Peer to peer technology to minimize the necessary upload bandwidth for the original IceShare is an unfinished Peercasting system for Ogg multimedia FreeCast is a Free software application which allows Peer-to-peer streaming sometimes called Peercasting. RawFlow is a provider of live p2p Streaming technology that enables internet Broadcasting of audio and video Pichat ( pitʃæt) is a chat software and a protocol for information exchange in a Peer-to-peer network Online chat can refer to any kind of Communication over the Internet, but is primarily meant to refer to direct one-on-one chat or Text-based group Collaborative software (also referred to as groupware or workgroup support systems) is software designed to help people involved in a common task achieve their Usenet, a Portmanteau of "user" and "network" is a world-wide distributed Internet discussion system WinMX is a Freeware Peer-to-peer File sharing program authored by Frontcode Technologies that runs on Microsoft Windows operating systems See Shared resource for the conventional meaning of file sharing File sharing refers to the providing and receiving of digital files over a WinMX is a Freeware Peer-to-peer File sharing program authored by Frontcode Technologies that runs on Microsoft Windows operating systems Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Windows XP is a family of 32-bit and 64-bit Operating systems produced by Microsoft for use on Personal computers including home and Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops This is a Windows component that runs only over IPv6 and provides a 'meta' peer-to-peer network that applications can utilize. Internet Protocol version 6 ( IPv6) is an Internet Layer protocol for packet -switched internetworks. It does not have file sharing support but third-parties can develop one. [8] It also includes the Peer Name Resolution Protocol that allows dynamic domain name publication and resolution of names to endpoints. This article needs more context around or a better explanation of technical details to make it more accessible to general readers Windows Meeting Space and the People Near Me feature of Windows Vista use this protocol. Windows Meeting Space (codenamed Windows Collaboration) is the name of a Peer-to-peer collaboration program in Windows Vista that supports It can be used to setup a Windows Internet Computer Name (WICN) using netsh p2p. In Software, netsh, or network shell, is a utility included in Microsoft 's Windows NT line of Operating systems beginning [10]

• Other networks: ANts P2P, Applejuice, Audiogalaxy, Avalanche, CAKE, Chord, The Circle, Coral, Dijjer, FileTopia, Groove, Hamachi, iFolder, konspire2b, Madster/Aimster, MUTE, OpenFT, P-Grid, IRC, JXTA, MojoNation, Mnet, Octoshape, Omemo, Overnet, Peersites, Perfect Dark, Scour, SharingZone, Skype, Solipsis, soribada, Soulseek, SPIN, Swarmcast, WASTE, Winny

An earlier generation of peer-to-peer systems were called "metacomputing" or were classed as "middleware". ANts P2P is an anonymous peer-to-peer Open source File sharing software written in Java. Applejuice is a semi-centralized Peer-to-peer File sharing network similar to the original EDonkey network. Audiogalaxy was a File sharing system that indexed MP3 files originally created by Michael Merhej as an FTP site index called The Borg Search Avalanche is the name of a proposed Peer-to-peer (P2P network created by Pablo Rodriguez and Christos Gkantsidis at Microsoft, which claims Chord is one of the original Distributed hash table protocols The Circle is a Peer-to-peer distributed file system written mainly in Python. The Coral Content Distribution Network, sometimes called Coral Cache or Coral for short is a free Peer-to-peer content distribution network Dijjer is a Peer-to-peer Web cache. It is "pure" P2P because it relies on the computers of those using it and is almost completely decentralized FileTopia is a free Windows-based client and networking tool allowing users to organize files text & voice recordings Chat, and Instant messages. Microsoft Office Groove is a desktop application designed for document Collaboration in teams with members who are regularly Off-line or who do not share the same Hamachi is a centrally-managed Zero-configuration Virtual private network (VPN Freeware application capable of establishing direct links between iFolder is an Open source application developed by Novell Inc konspire2b is a distributed, deniable, strongly- pseudonymous distribution system for files over a computer network Madster was one of the many P2P File sharing services that appeared in Napster 's wake The MUTE Network (or MUTE-net) is a Peer-to-peer and Friend-to-friend File sharing network developed with anonymity in mind OpenFT is a File sharing protocol developed by the GiFT project P-Grid is a self-organizing structured Peer-to-peer system which can accommodate arbitrary key distributions (and hence support lexicographic key ordering and range queries JXTA ( Juxtapose) is an Open source Peer-to-peer protocol specification begun by Sun Microsystems in 2001 Mnet is a distributed Peer to peer, file store (A Distributed file store is a shared virtual space into which you can put and from which you can Mnet is a distributed Peer to peer, file store (A Distributed file store is a shared virtual space into which you can put and from which you can Octoshape is a Peer to peer Streaming media server and client which uses Peer to peer grid technology to minimize the bandwidth for any broadcaster to stream Omemo is an open source social storage platform in which users share anonymously files on a part of their hard disks Overnet was a decentralized Peer-to-peer Computer network, usually used for sharing large files (e Peersites is a Peer-to-peer networks of peers gateways and peername services Perfect Dark is a Japanese Peer-to-peer File-sharing (P2P application designed for use with Microsoft Windows (not to be confused with the video game franchise For the physical process see Wiktionaryscouring. Scour Inc was a search engine for Skype (skaɪp is Software that allows users to make telephone calls over the Internet. Solipsis is a free and Open source system for a massively multi-participant shared Virtual world designed by Joaquin Keller and Gwendal Soribada ( Korean: 소리바다 is the first Korean Peer-to-peer system Soulseek is a File-sharing (also called Peer-to-peer or 'P2P' network and application It is used mostly to exchange music although users are able to share a variety Secure Peered Internet (SPIN is a network created by Outhink. Swarmcast was the first Peer-to-peer (P2P content delivery system and the originator of the term "Swarming Downloads WASTE is a Peer-to-peer and Friend-to-friend protocol and software application developed by Justin Frankel at Nullsoft in 2003 that features Winny (also known as WinNY) is a Japanese Peer-to-peer (P2P File-sharing program which claims to be loosely inspired by the design principles behind the These include: Legion, Globus

Multi-network applications

Main article: Comparison of file sharing applications

Applications	Network or Protocol	Operating systems	License
aMule	eDonkey network, Kad network	Cross-platform	GPL
DC++	BCDC++	Windows	GPL
eMule	eDonkey network, Kad network	Windows	GPL
giFT	eDonkey network, FastTrack, Gnutella	Cross-platform	GPL
Gnucleus	Gnutella, Gnutella2	Windows	GPL
Gtk-Gnutella	Gnutella	Linux	GPL
iMesh	FastTrack, eDonkey network, Gnutella, Gnutella2	Windows	Proprietary
KCeasy	Ares, FastTrack, Gnutella, OpenFT	Windows	GPL
Kiwi Alpha	Gnutella, Gnutella2	Windows	Proprietary
MLDonkey	BitTorrent, Direct Connect, eDonkey network, FastTrack, Gnutella, Gnutella2, Kad Network, OpenNap, SoulSeek, HTTP/FTP	Cross-platform	GPL
Morpheus	Gnutella, Gnutella2, BitTorrent	Windows	Proprietary
Shareaza	Gnutella, Gnutella2, eDonkey, BitTorrent, HTTP/FTP	Windows	GPL
Vagaa	BitTorrent, eDonkey, Kad	Windows	Proprietary
Zultrax	Gnutella, ZEPP	Windows	Proprietary

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
• May, 2001: first release of WinMX Peer Network Protocol
• July, 2001: shutdown of Napster
• November 6, 2001: first release of GNUnet
• March, 2002: publication of the Kademlia DHT
• November, 2002: start of the Gnutella2 project

See also

References

External links

• Foundation of Peer-to-Peer Computing, Special Issue, Elsevier Journal of Computer Communication, (Ed) Javed I. Khan and Adam Wierzbicki, Volume 31, Issue 2, February 2008
• Ross J. Anderson. The eternity service. In Pragocrypt 1996, 1996.

• Marling Engle & J. I. Khan. Vulnerabilities of P2P systems and a critical look at their solutions, May 2006

• Carsten Rossenhövel, Peer-to-Peer Filters: The Big Report. Internet Evolution, March 2008

• Stephanos Androutsellis-Theotokis and Diomidis Spinellis. A survey of peer-to-peer content distribution technologies. ACM Computing Surveys, 36(4):335–371, December 2004.

• Biddle, Peter, Paul England, Marcus Peinado, and Bryan Willman, The Darknet and the Future of Content Distribution. In 2002 ACM Workshop on Digital Rights Management, November 2002.

• Detlef Schoder and Kai Fischbach, Core Concepts in Peer-to-Peer (P2P) Networking. In: Subramanian, R. ; Goodman, B. (eds. ): P2P Computing: The Evolution of a Disruptive Technology, Idea Group Inc, Hershey. 2005

• Ralf Steinmetz, Klaus Wehrle (Eds). Peer-to-Peer Systems and Applications. ISBN 3-540-29192-X, Lecture Notes in Computer Science, Volume 3485, September 2005.

• Ramesh Subramanian and Brian Goodman (eds), Peer-to-Peer Computing: Evolution of a Disruptive Technology, ISBN 1-59140-429-0, Idea Group Inc. , Hershey, PA, USA, 2005.

• Shuman Ghosemajumder. Shuman Ghosemajumder (born 1974 is a Canadian technologist businessman and author based in Silicon Valley. Advanced Peer-Based Technology Business Models. MIT Sloan School of Management, 2002.

• Silverthorne, Sean. Music Downloads: Pirates- or Customers?. Harvard Business School Working Knowledge, 2004. Harvard Business School ( HBS) is a renowned Business school in the United States

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org