As computer use in
businesses grew, it soon became apparent that even LANs were not
sufficient. In a LAN system, each department, or business was a kind
of electronic island. What was needed was a way for information to
move efficiently and quickly from one business to another.
The solution was the creation of wide area networks (WANs). WANs
interconnected LANs, which then provided access to computers or file
servers in other locations. Because WANs connected user networks over
a large geographical area, they made it possible for businesses to
communicate with each other across great distances. As a result of
being networked or connected, computers, printers, and other devices
on a WAN could communicate with each other to share information and
resources, as well as to access the Internet.
Some common WAN technologies are:
- modems
- ISDN (Integrated Services Digital Network)
- DSL (Digital Subscriber Line)
- Frame relay
- ATM (Asynchronous Transfer Mode)
- The T (US) and E (Europe) Carrier Series: T1, E1, T3, E3, etc.
- SONET (Synchronous Optical Network)
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