WAN Concepts and Terminology

A WAN is different from a LAN. Unlike a LAN, which connects workstations, peripherals, terminals, and other devices in a single building or other small geographic area, a WAN makes data connections across a broad geographic area. Companies use the WAN to connect various company sites together so information can be exchanged between distant offices

WAN Connection Types

Leased Lines
A leased line, also known as a point-to-point or dedicated connection, provides a single, preestablished WAN communications path from the customer premises, through a service provider network, to a remote network This connection is reserved by the service provider for the client&qt;&qt;s private use.

Circuit Switching
Circuit switching is a switching system in which a dedicated circuit path must exist between sender and receiver for the duration of the "call." Circuit switching is used by the service provider network when providing basic telephone service or Integrated Services Digital Network (ISDN). Circuit switched connections are commonly used in environments that require only sporadic WAN usage. Basic telephone service is typically employed over an asynchronous serial connection.

Packet Switching
Packet switching is a WAN switching method in which network devices share a single point-to-point link to transport packets from a source to a destination across a carrier network. Packet switched networks use virtual circuits (VCs) that provide end-to-end connectivity. Physical connections are provided by programmed switching devices.