|
|
|
|
Wide Area Network
The wide area network (WAN) is a communications network that connects local computer networks into a larger working network that may cover both national and international locations. In 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 respectively. The largest and most well-known example of a WAN is the Internet.
WANs are often built using leased lines. At each end of the leased line, a router 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 or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH, MPLS, ATM and Frame relay are often used by service providers to deliver the links that are used in WANs. X.25 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 are still in use today (with upgrades) by Frame Relay.
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 connectivity many companies and organizations have turned to VPN to interconnect their networks, creating a WAN in that way. Companies such as Cisco, New Edge Networks and Check Point offer solutions to create VPN networks.
WAN usage
With coverage in a broad area, a wide area network allows companies to make use of common resources in order to operate. For example, many retail drugstores make use of a wide area network as part of their support to customers who fill prescriptions with one of their stores. Once in the common customer database for the pharmacy, the client is free to fill a prescription at any of the company’s locations, even while vacationing in another state.
Companies also make good use of the wide area network as well. Internal functions such as sales, production and development, marketing and accounting can also be shared with authorized locations through this sort of broad area network application. The concept of a wide area network as a means of taking individual location based computer networks and using them to create a unified computer network for the entire corporation means that employees can work from just about anywhere. Should one facility be damaged or rendered inaccessible due to natural disaster, employees simply move to another location where they can access the unified network, and keep on working.
Comments (0)
Write comment