A wide-area network may consist simply of dialup connections between systems using analog modems at the low-end. At the other extreme are the emerging technologies that will permit data, sound, and video to be simultaneously transmitted across wide geographies through high-speed digital services.

A wide-area network is generally implemented through the use of public carriers. The most common of these is the phone company. Public carriers can offer simply a circuit connection, or they can offer a transport service that includes the circuits, the communications protocols for data exchange, and a gateway or protocol converter that allows data traffic to be translated into the wide-area protocol, transmitted, and converted back at the other end.

When a customer chooses to use a dial-up or leased line, they supply the hardware (analog modems or CSU/DSU digital modems) at each end of the connection to supply the necessary transmission protocols to transport the data. These are commonly point-to-point links between two specific locations.

An alternative to dial-up or leased-lines is a public data network (PDN). When a customer uses a public network, they attach to the public network each location they want to reach, and either the carrier or the customer supplies a gateway device that converts between the PDN transmission protocols and the local area protocols at each end. PDNs are often called clouds, implying that data goes into the cloud at one point and comes out at another. PDNs are generally set up with mesh topologies, which allows them to route traffic through multiple pathways. PDNs set up virtual circuits between locations, that exist for the duration of the data transmission. Routing within the public network is achieved using packet switches.

A frequently-used device with wide-area circuits is a multiplexer (MUX). A multiplexer takes several data streams and combines them into one signal for transmission across the circuit, and then another MUX at the other end separates the signals out at the destination. Many companies, including CompuCom, use MUXES to transmit digital telephone and data traffic between locations using the same wide-area link.