Chapter . WAN Technologies

Moving Information Across Vast Areas

How does a company connect the network in its New York office to the network in its Los Angeles office? It doesn’t make sense to run a cable across the United States. Instead, the company subscribes to wide area services.

A wide-area network (WAN) is a network that covers a broad geographic area and often uses transmission facilities provided by common carriers. WAN functionality occurs at Layers 1–3 in the Open System Interconnection (OSI) reference model. The bicoastal company in the example would contact its service provider to purchase WAN connectivity between the offices. WAN services are leased from service providers with either a monthly flat fee or a per-usage charge. More bandwidth ...

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