Because businesses are rarely housed in a single building and because customers are typically scattered across a broad geographical area (particularly multinational customers), there is a growing need for high-speed, reliable wide area transport. Wide area can take on a variety of meanings. For example, a company with multiple offices scattered across the metropolitan expanse of a large city requires interoffice connectivity in order to do business properly. On the other hand, a large multinational company with offices and clients in Madrid, San Francisco, Hamburg, and Singapore requires connectivity to ensure that the offices can exchange information on a 24-hour basis.

These requirements are satisfied through the proper deployment of wide area transport technologies. These can be as simple as a dedicated private-line circuit or as complex as a virtual installation that relies on ATM for high-quality transport.

Dedicated facilities are excellent solutions because they are dedicated. They provide fixed bandwidth that never varies and guarantee the quality of the transmission service. Because they are dedicated, however, they suffer from two disadvantages. First, they are expensive and only cost-effective when highly utilized. The pricing model for dedicated circuits includes two components: the mileage of the circuit and the bandwidth. The longer the circuit and the faster it is, the more it costs. Second, because they are not switched and are often not redundant because of cost, dedicated facilities pose the potential threat of a prolonged service outage should they fail. Nevertheless, dedicated circuits are popular for certain applications...