Metropolitan Area Networks (MANs) / Wide Area Networks (WANs)

MANs

The next larger network than LAN may be the Metropolitan Area Networks (MANs). MAN usually spans a geographical area that usually encompasses a city or county area. It interconnects various buildings or other facilities within this citywide area. For example, linkages can be established between two commercial buildings. A more recent use of MAN technology has been the rapid development of cellular phone systems.

A wide area network (WAN) is one that operates over a vast distance (e.g., nationwide). Its nodes may span cities, states, or national boundaries. This network interconnects computers, LANS, BNs, MANS, and other data transmission facilities. Typically, WAN will employ communications circuits such as long- distance telephone wires, microwaves and satellites. FOR example, nationwide automated teller machines used in banking represent a common application of a wide area network.

Backbone Networks

A BN is a large network to which many networks within an organization are connected. It usually is a network that interconnects all networks on a single site, but it can be larger if it connects all the organization's terminals, microcomputers, mainframes, local area networks, and other communication equipment.

NetBIOS

NETwork Basic Input/Output System is a commonly used transmission protocol for PC LANs. This is an extension to DOS, which examines all functions and direct to DOS. It provides a program called "redirector" that resides on top of DOS.