A Wide Area Network (WAN) is any network that spans a distance usually measured in miles or kilometers and which is used to connect one or more Local Area Networks (LAN) utilizing ATM, Serial lines such as T1 and T3 or fiber optic technologies utilizing SONET.
The term WAN is a generic description for large networks spanning long distances, usually across counties, states and international borders. WANs as a group tend to have high delay through the network because of the distances spanned by the network, even when they have plenty of bandwidth capacity.
Speaking generally:
- A WAN spans a long distance
- Transmission across a WAN is usually slower than on a LAN
- WANs rarely use broadcast, multiaccess technologies
- WANs are usually composed of leased lines and telecommunications circuits.
- WANs are not usually used to connect computer workstations or servers
- WANs are often used to interconnect datacenters