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Wide Area Network (WAN) is a computer network
Computer network

A computer network is a group of interconnected computers. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of some types and categories and also presents the basic components of a network....
 that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries ). Contrast with personal area network
Personal area network

A personal area network is a computer network used for communication among computer devices close to one person. The devices may or may not belong to the person in question....
s (PANs), local area network
Local area network

A local area network is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport....
s (LANs), campus area network
Campus area network

A campus area network is a computer network made up of an interconnection of local area networks within a limited geographical area. It can be considered one form of a metropolitan area network, specific to an academic setting....
s (CANs), or metropolitan area network
Metropolitan area network

Metropolitan area networks, or MANs, are large computer networks usually spanning a city. They typically use wireless infrastructure or Optical fiber connections to link their sites....
s (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet
Internet

The Internet is a global network of interconnected computers, enabling users to share information along multiple channels. Typically, a computer that connects to the Internet can access information from a vast array of available server and other computers by moving information from them to the computer's local memory....
.

WANs [a] are used to connect LANs and other types of networks together, so that users and computers in one location can communicate with users and computers in other locations.






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Wide Area Network (WAN) is a computer network
Computer network

A computer network is a group of interconnected computers. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of some types and categories and also presents the basic components of a network....
 that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries ). Contrast with personal area network
Personal area network

A personal area network is a computer network used for communication among computer devices close to one person. The devices may or may not belong to the person in question....
s (PANs), local area network
Local area network

A local area network is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport....
s (LANs), campus area network
Campus area network

A campus area network is a computer network made up of an interconnection of local area networks within a limited geographical area. It can be considered one form of a metropolitan area network, specific to an academic setting....
s (CANs), or metropolitan area network
Metropolitan area network

Metropolitan area networks, or MANs, are large computer networks usually spanning a city. They typically use wireless infrastructure or Optical fiber connections to link their sites....
s (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet
Internet

The Internet is a global network of interconnected computers, enabling users to share information along multiple channels. Typically, a computer that connects to the Internet can access information from a vast array of available server and other computers by moving information from them to the computer's local memory....
.

WANs [a] are used to connect LANs and other types of networks together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service provider
Internet service provider

An Internet service provider is a company that offers its customers access to the Internet. The ISP connects to its customers using a data transmission technology appropriate for delivering Internet Protocol datagrams, such as dial-up, DSL, cable modem or dedicated high-speed interconnects....
s, provide connections from an organization's LAN to the Internet. WANs are often built using leased line
Leased line

A leased line is a Symmetric#Symmetry_in_telecommunications telecommunications line connecting two locations. It is sometimes known as a 'Private Circuit' or 'Data Line' in the UK....
s. At each end of the leased line, a router
Router

A router is a Computer network device whose software and hardware are usually tailored to the tasks of routing and forwarding information. For example, on the Internet, information is directed to various paths by routers....
 connects to the LAN on one side and a hub within the WAN on the other. Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching
Circuit switching

In telecommunications, a circuit switching network is one that establishes a telecommunication circuit between Node and Terminal before the user may communicate, as if the nodes were physically connected with an electrical circuit....
 or packet switching
Packet switching

Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets....
 methods. Network protocols
Communications protocol

In the field of telecommunications, a communications protocol is the set of standard rules for data representation, Signalling , authentication and Error detection and correction required to send information over a communications channel....
 including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH
Packet over SONET/SDH

Packet over SONET/SDH, abbreviated POS, is a communications protocol for transmitting Packet in the form of the Point to Point Protocol over Synchronous_optical_networking or SONET, which are both standard protocols for communicating digital information using lasers or light emitting diodes over optical fibre at high line rates....
, MPLS
Multiprotocol Label Switching

In computer networking and telecommunications, Multi Protocol Label Switching refers to a highly scalable, protocol agnostic, data-carrying mechanism....
, ATM
Asynchronous Transfer Mode

Asynchronous Transfer Mode is an electronic digital data transmission technology. ATM is implemented as a network protocol and was first developed in the mid 1980s....
 and Frame relay
Frame relay

In the context of computer networking, frame relay consists of an efficient data transmission technique used to send digital information. It is a message forwarding "relay race" like system in which data packets, called data frames, are passed from one or many start-points to one or many destinations via a series of intermediate node points....
 are often used by service providers to deliver the links that are used in WANs. X.25
X.25

X.25 is an ITU-T standard network layer protocol for Packet switched network wide area network communication. An X.25 WAN consists of Packet switching nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links....
 was an important early WAN protocol, and is often considered to be the "grandfather" of Frame Relay as many of the underlying protocols and functions of X.25
X.25

X.25 is an ITU-T standard network layer protocol for Packet switched network wide area network communication. An X.25 WAN consists of Packet switching nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links....
 are still in use today (with upgrades) by Frame Relay.

Academic research into wide area networks can be broken down into three areas: Mathematical model
Mathematical model

A mathematical model uses mathematics language to describe a system. Mathematical models are used not only in the natural sciences and engineering disciplines but also in the social sciences ; physicists, engineers, computer sciences, and economists use mathematical models most extensively....
s, network emulation
Network emulation

Network emulation is a technique where the properties of an existing, planned and/or non-ideal telecommunications network are simulated in order to assess performance, predict the impact of change, or otherwise optimize technology decision-making....
 and network simulation
Network simulation

In communication and computer network research, network simulation is a technique where a program models the behavior of a network either by calculating the interaction between the different network entities using mathematical formulas, or actually capturing and playing back observations from a production network....
.

Performance improvements are sometimes delivered via WAFS
Wide area file services

Wide area file services products allow remote office users to access and share files globally at LAN speeds over the Wide area network. Distributed enterprises that deploy WAFS solutions are able to consolidate storage to corporate datacenters, eliminating the need to back up and manage data that previously resided in their remote offices....
 or WAN optimization
WAN Optimization

WAN optimization products seek to accelerate a broad range of applications accessed by distributed enterprise users via eliminating redundant transmissions, staging data in local caches, compressing and prioritizing data, and streamlining chatty protocols ....
.

Several options are available for WAN connectivity:
Option: Description Advantages Disadvantages Bandwidth range Sample protocols used
Leased line
Leased line

A leased line is a Symmetric#Symmetry_in_telecommunications telecommunications line connecting two locations. It is sometimes known as a 'Private Circuit' or 'Data Line' in the UK....
 Point-to-Point connection between two computers or Local Area Networks (LANs) Most secure Expensive PPP
Point-to-Point Protocol

In Computer network, the Point-to-Point Protocol, or PPP, is a Data Link Layer Protocol commonly used to establish a direct connection between two Node ....
, HDLC, SDLC
Synchronous Data Link Control

Synchronous Data Link Control is a computer communications protocol. It is the layer 2 protocol for IBM's Systems Network Architecture . SDLC supports multipoint links as well as error correction....
, HNAS
Circuit switching
Circuit switching

In telecommunications, a circuit switching network is one that establishes a telecommunication circuit between Node and Terminal before the user may communicate, as if the nodes were physically connected with an electrical circuit....
 A dedicated circuit path is created between end points. Best example is dialup connections Less Expensive Call Setup 28 kbit/s - 144 kbit/s PPP
Point-to-Point Protocol

In Computer network, the Point-to-Point Protocol, or PPP, is a Data Link Layer Protocol commonly used to establish a direct connection between two Node ....
, ISDN
Packet switching
Packet switching

Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets....
 Devices transport packets via a shared single point-to-point or point-to-multipoint link across a carrier internetwork. Variable length packets are transmitted over Permanent Virtual Circuits (PVC) or Switched Virtual Circuits (SVC) Shared media across link X.25
X.25

X.25 is an ITU-T standard network layer protocol for Packet switched network wide area network communication. An X.25 WAN consists of Packet switching nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links....
 Frame-Relay
Cell relay
Cell relay

In telecommunications, cell relay refers to a method of statistical multiplexing fixed-length packet , i.e. cells, to transport data between computers or kinds of network equipment....
 Similar to packet switching, but uses fixed length cells instead of variable length packets. Data is divided into fixed-length cells and then transported across virtual circuits best for simultaneous use of Voice and data Overhead
Overhead

Overhead may be:* Overhead , the ongoing operating costs of running a business* Engineering overhead, ancillary design features required by a component of a device...
 can be considerable 		ATM
Asynchronous Transfer Mode

Asynchronous Transfer Mode is an electronic digital data transmission technology. ATM is implemented as a network protocol and was first developed in the mid 1980s....


Transmission rate usually range from 1200 bits/s to 6 Mbit/s, although some connections such as ATM and Leased lines can reach speeds greater than 156 Mbit/s. Typical communication links used in WANs are telephone lines, microwave links & satellite channels.

Recently with the proliferation of low cost of Internet
Internet

The Internet is a global network of interconnected computers, enabling users to share information along multiple channels. Typically, a computer that connects to the Internet can access information from a vast array of available server and other computers by moving information from them to the computer's local memory....
 connectivity many companies and organizations have turned to VPN to interconnect their networks, creating a WAN in that way. Companies such as Cisco
Cisco

Cisco may refer to:Companies:* Cisco Systems, a computer networking company* Certis CISCO, corporatised entity of the former Commercial and Industrial Security Corporation in Singapore....
, New Edge Networks and Check Point
Check Point

Check Point Software Technologies Ltd. is a hardware and software company that is best known for its firewall and VPN products. The company was founded in 1993 in Ramat-Gan, Israel, by Gil Shwed, Shlomo Kramer, and Marius Nacht....
 offer solutions to create VPN networks.

See also

  • Computer network
    Computer network

    A computer network is a group of interconnected computers. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of some types and categories and also presents the basic components of a network....
  • Personal area network (PAN)
    Personal area network

    A personal area network is a computer network used for communication among computer devices close to one person. The devices may or may not belong to the person in question....
  • Local area network (LAN)
    Local area network

    A local area network is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport....
  • Storage area network (SAN)
    Storage area network

    A storage area network is an architecture to attach remote computer storage devices to Server s in such a way that the devices appear as Direct-attached storage to the operating system....
  • Campus area network (CAN)
    Campus area network

    A campus area network is a computer network made up of an interconnection of local area networks within a limited geographical area. It can be considered one form of a metropolitan area network, specific to an academic setting....
  • Metropolitan area network (MAN)
    Metropolitan area network

    Metropolitan area networks, or MANs, are large computer networks usually spanning a city. They typically use wireless infrastructure or Optical fiber connections to link their sites....
  • Internet
    Internet

    The Internet is a global network of interconnected computers, enabling users to share information along multiple channels. Typically, a computer that connects to the Internet can access information from a vast array of available server and other computers by moving information from them to the computer's local memory....
  • Leased Line
    Leased line

    A leased line is a Symmetric#Symmetry_in_telecommunications telecommunications line connecting two locations. It is sometimes known as a 'Private Circuit' or 'Data Line' in the UK....
  • Circuit Switching
    Circuit switching

    In telecommunications, a circuit switching network is one that establishes a telecommunication circuit between Node and Terminal before the user may communicate, as if the nodes were physically connected with an electrical circuit....
  • Packet Switching
    Packet switching

    Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets....
  • Cell Switching
  • Label Switching
    Label switching

    Label switching is a technique of computer network relaying to overcome the problems perceived by traditional internet protocol-table switching ....
  • X.25
    X.25

    X.25 is an ITU-T standard network layer protocol for Packet switched network wide area network communication. An X.25 WAN consists of Packet switching nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links....
  • Frame Relay
    Frame relay

    In the context of computer networking, frame relay consists of an efficient data transmission technique used to send digital information. It is a message forwarding "relay race" like system in which data packets, called data frames, are passed from one or many start-points to one or many destinations via a series of intermediate node points....
  • ATM
    Asynchronous Transfer Mode

    Asynchronous Transfer Mode is an electronic digital data transmission technology. ATM is implemented as a network protocol and was first developed in the mid 1980s....
  • SONET/SDH
  • MPLS
    Mpls

    MPLS or Mpls can refer to:* Minneapolis, Minnesota, United States* Multiprotocol Label Switching, a data-carrying mechanism in computer networking...
  • Wireless Wide Area Network (WWAN)
  • Wide Area File Services (WAFS)
    Wide area file services

    Wide area file services products allow remote office users to access and share files globally at LAN speeds over the Wide area network. Distributed enterprises that deploy WAFS solutions are able to consolidate storage to corporate datacenters, eliminating the need to back up and manage data that previously resided in their remote offices....
  • Wide Area Application Services (WAAS)
    Wide area application services

    Cisco Wide Area Application Services is technology developed by Cisco Systems that optimizes the performance of any TCP-based application operating in a wide area network environment while preserving and strengthening branch security....


External links