- Wide area network
Wide Area Network (WAN) is a
computer networkthat covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries cite book
first = David
coauthors = Toby Skandier
title = 'Network+ Study Guide, Fourth Edition'
publisher = Sybex, Inc.
date = 2005
id = ISBN 0-7821-4406-3 ] ). Less formally, a WAN is a network that uses routers and public
communications links . Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (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.
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 providers, provide connections from an organization's LAN to the Internet. WANs are often built using leased lines. At each end of the leased line, a routerconnects 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 switchingor packet switchingmethods. Network protocols including TCP/IPdeliver transport and addressing functions. Protocols including Packet over SONET/SDH, MPLS, ATM and Frame relayare often used by service providers to deliver the links that are used in WANs. X.25was 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.25are still in use today (with upgrades) by Frame Relay.
Academic research into wide area networks can be broken down into three areas:
Mathematical models, network emulationand network simulation.
Performance improvements are sometimes delivered via WAFS or
Several options are available for WAN connectivity: [cite book
first = Steve
title = 'CCNA Self-Study: Interconnecting Cisco Network Devices (ICND), Second Edition'
publisher = Cisco Press
November 19 2003
id = ISBN 1-58705-142-7 ]
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
Internetconnectivity many companies and organizations have turned to VPNto interconnect their networks, creating a WAN in that way. Companies such as Cisco, New Edge Networks and Check Pointoffer solutions to create VPN networks.
*Personal area network (PAN)
*Local area network (LAN)
*Storage area network (SAN)
*Campus area network (CAN)
*Metropolitan area network (MAN)
*Wireless Wide Area Network (WWAN)
*Wide Area File Services (WAFS)
*Wide Area Application Services (WAAS)
* [http://www.cisco.com/en/US/docs/internetworking/technology/handbook/Intro-to-WAN.html Cisco - Introduction to WAN Technologies]
* [http://www.entryboot.com/wireless-wide-area-network.php Wireless Wire Area Network]
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