A computer network is a system for communication among two or more computers. These networks may be fixed (cabled, permanent) or temporary (as via modems). Communication is the process of exchanging information usually via a common system of symbols. ... A computer is a device or machine for making calculations or controlling operations that are expressible in numerical or logical terms. ... A wide variety of systems of interconnected components are called networks. ... A modem (a portmanteau word constructed from modulator and demodulator) is a device that modulates an analog carrier signal (sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information. ...

Categorizing

• local area network (LAN)
  • HomePNA
  • Power line communication (HomePlug)
• metropolitan area network (MAN)
• wide area network (WAN)

A local area network (LAN) is a computer network covering a local area, like a home, office or small group of buildings such as a college. ... This article needs to be cleaned up to conform to a higher standard of quality. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Metropolitan Area Networks or MANs are large computer networks usually spanning a campus or a city. ... A wide area network or WAN is a computer network covering a wide geographical area, involving vast array of computers. ...

By functional relationship

• client-server
• multitier architecture
• peer-to-peer

Client/Server is a network application architecture which separates the client (usually the graphical user interface) from the server. ... In software engineering, multi-tier architecture (often referred to as n-tier architecture) is a client-server architecture in which an application is executed by more than one distinct software agent. ... A peer-to-peer (or P2P) computer network is any network that does not rely on dedicated servers for communication but instead mostly uses direct connections between clients (peers). ...

By network topology

• bus network
• star network
• ring network
• mesh network
• star-bus network

A network topology is the method in which nodes of a network are connected by links. ... A bus network is a network architecture in which a set of clients are connected via a shared communications line, called a bus. ... A computer network with a star network topology, in its simplest form, consists of one central, or hub computer which acts as a router to transmit messages. ... A ring network is a topology of computer networks where each user is connected to two other users, so as to create a ring. ... Mesh networking is a way to route data, voice and instructions between nodes. ... A star-bus network is a combination of a star network and a bus network. ...

By specialized function

• Storage area networks
• Server farms
• Process control networks
• Value added network
• SOHO network
• Wireless community network

In computing, a storage area network (SAN) is a network designed to attach computer storage devices such as disk array controllers and tape libraries to servers. ... A typical server farm. ... A Process Control Network (PCN) is a communications network that is used to transmit instructions and data between control and measurement units and Supervisory Control and Data Acquisition (SCADA) equipment. ... Categories: Move to Wiktionary | Substubs ... A SOHO network is a Small office/home office local area network. ... Wireless community networks or wireless community projects are the largely hobbyist-led development of interlinked computer networks using wireless LAN technologies, taking advantage of the recent development of cheap, standardised 802. ...

Protocol stacks

Computer networks may be implemented using a variety of protocol stack architectures, computer buses or combinations of media and protocol layers, incorporating one or more of: A protocol stack is a particular software implementation of a computer networking protocol suite. ... In computer architecture, a bus is a subsystem that transfers data or power between computer components inside a computer or between computers. ...

• ARCNET
• DECnet
• Ethernet
• IP
• TCP
• UDP
• AppleTalk
• Token Ring
• IPX
• SPX
• FDDI
• HIPPI
• Myrinet
• QsNet
• ATM
• RS-232
• IEEE-488
• USB
• IEEE 1394 aka Firewire, iLink
• X.25
• Frame relay
• Bluetooth
• IEEE 802.11
• System Network Architecture

For a list of more see Network protocols ARCNET (also camel cased as ARCnet, an acronym from Attached Resource Computer NETwork) is a local area network (LAN) protocol, similar in purpose to Ethernet or Token Ring. ... DECnet is a proprietary suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. ... Ethernet (this name comes from the physical concept of ether) is a frame based computer networking technology for local area networks (LANs). ... The Internet Protocol (IP) is a data-oriented protocol used by source and destination hosts for communicating data across a packet-switched internetwork. ... The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. ... The User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite. ... AppleTalk is a suite of protocols developed by Apple Computer for computer networking. ... Token-Ring local area network (LAN) technology, developed and promoted by IBM in the early 1980s and standardised as IEEE 802. ... Internetwork Packet Exchange (IPX) is at the Network layer of the OSI model and is part of the IPX/SPX protocol stack. ... Sequenced Packet Exchange (SPX) is an old Novell protocol used to manage the Novell Internetwork Packet Exchange (IPX) that allowed Novell Servers and clients to communicate over LAN (Local Area Networks) and WAN (Wide Area Networks). ... In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ... HIPPI (HIgh Performance Parallel Interface) is a computer bus for the attachment of high speed storage devices to supercomputers. ... Myrinet, ANSI/VITA 26-1998, is a high-speed local area networking system designed by Myricom to be used as an interconnect between multiple machines to form computer clusters. ... QsNet is a high speed interconnect designed by Quadrics used in HPC clusters, particularly Linux Beowulf Clusters. ... Asynchronous Transfer Mode, or ATM for short, is a cell relay network protocol which encodes data traffic into small fixed sized (53 byte; 48 bytes of data and 5 bytes of header information) cells instead of variable sized packets as in packet-switched networks (such as the Internet Protocol or... RS-232 (also referred to as EIA RS-232C or V.24) is a standard for serial binary data interchange between a DTE (Data terminal equipment) and a DCE (Data communication equipment). ... The Hewlett-Packard Instrument Bus (HP-IB), is a short-range digital communications cable standard developed by Hewlett-Packard (HP) in the 1970s for connecting electronic test and measurement devices (e. ... Type A USB connector USB 2. ... A 6-Pin Firewire 400 connector FireWire (also known as i. ... X.25 is an ITU-T standard protocol suite for WAN networks using the phone or ISDN system as the networking hardware. ... Frame relay, also found written as frame-relay, is an efficient data transmission technique used to send digital information quickly and cheaply to one or many destinations from one or many end-points. ... This article is about the Bluetooth wireless specification. ... IEEE 802. ... Systems Network Architecture (SNA) is IBMs proprietary networking architecture created in 1974. ... In networking, a communications protocol or network protocol is the specification of a set of rules for a particular type of communication. ...

For standards see IEEE 802. IEEE 802 refers to a family of IEEE standards about local area networks and metropolitan area networks. ...

Suggested topics

Further reading for acquiring an in-depth understanding of computer networks include:

• Communication theory

See information theory for information related to electronic communications. ...

Layers

The Open Systems Interconnection Reference Model (OSI Model or OSI Reference Model for short) is a layered abstract description for communications and computer network protocol design, developed as part of the Open Systems Interconnect initiative. ... The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet runs. ... The application layer is the seventh (7) level of the seven-layer OSI model. ... The presentation layer is the sixth level of the seven layer OSI model. ... The session layer is level five of the seven level OSI model. ... In computing and telecommunications, the transport layer is layer four of the seven layer OSI model. ... The network layer is level three of the seven level OSI model. ... This article is about electrical switches. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The data link layer is level two of the seven-level OSI model. ... The physical layer is level one in the seven level OSI model of computer networking. ...

Data transmission

• Wired transmission
  • Public switched telephone network
    • Modems and dialup
  • Dedicated lines – leased lines
  • Time-division multiplexing
  • Packet switching
  • Frame relay
  • PDH
  • Ethernet
  • RS-232
  • Optical fiber transmission
    • Synchronous optical networking
    • Fiber distributed data interface
• Wireless transmission
  • Short range
    • Bluetooth
  • Medium range
    • IEEE 802.11
  • Long range
    • Satellite
    • MMDS
    • SMDS
    • Mobile phone data transmission (channel access methods)
      • CDMA
      • CDPD
      • GSM
      • TDMA
    • Paging networks
      • DataTAC
      • Mobitex
      • Motient

Data transmission is, very generally speaking, the conveyance of any kind of information from one space to another. ... A wire is a single, usually cylindrical, elongated strand of drawn metal. ... The public switched telephone network (PSTN) is the concatenation of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the concatenation of the worlds public IP-based packet-switched networks. ... A modem (a portmanteau word constructed from modulator and demodulator) is a device that modulates an analog carrier signal (sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information. ... In computer networks and telecommunications, a dedicated line is a communications cable dedicated to a specific application, in contrast with a shared resource such as the telephone network or the Internet. ... A leased line is a (usually) symmetric telecommunications line connecting two locations together. ... Time-division multiplexing (TDM) is a type of digital multiplexing in which two or more apparently simultaneous channels are derived from a given frequency spectrum, i. ... In computer networking and telecommunications, packet switching is a communications paradigm in which packets (messages or fragments of messages) are individually routed between nodes, with no previously established communication path. ... Frame relay, also found written as frame-relay, is an efficient data transmission technique used to send digital information quickly and cheaply to one or many destinations from one or many end-points. ... == HeadlLink titleLink titleInsert non-formatted text hereInsert non-formatted text here ine text == Headline text Headline text Headline text The Plesiochronous Digital Hierarchy (PDH) is a technology used in telecommunications networks to transport large quantities of data over digital transport equipment such as fibre optic and microwave radio systems. ... Ethernet (this name comes from the physical concept of ether) is a frame based computer networking technology for local area networks (LANs). ... RS-232 (also referred to as EIA RS-232C or V.24) is a standard for serial binary data interchange between a DTE (Data terminal equipment) and a DCE (Data communication equipment). ... Optical fibers An optical fiber is a transparent thin fiber, usually made of plastic, for transmitting light. ... Synchronous Optical Networking, commonly known as SONET, is a standard for communicating digital information over optical fiber. ... In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ... Wireless was an old-fashioned term for a radio receiver, referring to its use as a wireless telegraph. ... This article is about the Bluetooth wireless specification. ... IEEE 802. ... A satellite is an object that orbits another object (known as its primary). ... Multichannel multipoint distribution service, also known as MMDS or wireless cable, is a wireless telecommunications technology, used for general-purpose broadband networking or, more commonly, as an alternative method of cable television programming reception. ... SMDS, which stands for Switched Multi-megabit Data Services, was a connectionless service used to connect LANs, MANs and WANs to exchange data. ... In communications, a channel access method is used to share a communications channel or physical communications medium between multiple users. ... Code division multiple access (CDMA) is a method of multiple access that does not divide up the channel by time (as in TDMA), or frequency (as in FDMA), but instead encodes data with a certain code associated with a channel and uses the constructive interference properties of the signal medium... Cellular Digital Packet Data (CDPD) uses unused bandwidth normally used by AMPS mobile phones between 800 and 900 MHz to transfer data. ... The Global System for Mobile Communications (GSM) is the most popular standard for mobile phones in the world. ... Time Division Multiple Access (TDMA) is a technology for shared medium (usually radio) networks. ... There are two related meanings to the word Paging in telecommunications. ... Mobitex is a paging network developed by Ericsson. ...

Other

• Computer networking device
  • Network card
• Naming schemes
• Network monitoring

Computer networking devices are units, that mediate data in a computer network. ... A transitional network card with both BNC Thinnet (left) and Twisted pair (right) connectors. ... A naming scheme is a plan for naming objects. ... The term network monitoring describes the use of a system that constantly monitors a computer network for slow or failing systems and that notifies the network administrator in case of outages via email, pager or other alarms. ...

See also

• Computing
• ARPANET
• BITNET
• Internet
  • Internet networks:
    • Backbone
    • Transit
    • Stub

Originally, the word computing was synonymous with counting and calculating, and a computer was a person who computes. ... ARPANET logical map, March 1977. ... BITNET was a cooperative U.S. university network founded in 1981 under the aegis of Ira Fuchs and Greydon Freeman at the City University of New York (CUNY). ... The Internet backbone was the central network that linked all the parts of the Internet together. ... The word transit, when used alone, has several possible meanings in English a modern rock band in Dallas, TX - [[]http://www. ... A Stub network is a slightly casual term describing a computer network, or part of an internetwork, that meets one or more of the following criteria (paraphrased from various sources): A single OSPF area with no external routes (though it may have interarea and/or intra-area routes). ...

References

• Andrew S. Tanenbaum, "Computer Networks" (ISBN 0133499456).
• Important publications in computer networks

Andrew S. Tanenbaum Andrew Stuart Andy Tanenbaum (born 1944) is a professor of Computer Science at Vrije Universiteit, Amsterdam in the Netherlands. ... This is a list of important publications in computer science, organized by field. ...

External links

• Networking and Microcomputers
• Network - eLook Computing Reference - defines what a network is and provides leading links
• Networking: K-12
• Networking dictionary
• Prof. Rahul Banerjee's free e-book on Internetworking Technolgies deals with the foundations of major internetworking architectures. (chapters 4-9) [1]