Data networks that reach across large distances (across states or even continents), known as wide-area networks or WANs, have different requirements and network packet-switching technologies than those that span much shorter distances (within a single building or room) characterized by local-area networks or LANs. The differentiating factor separating the two types of networks is more of technology than distance, because there is no set maximum distance for WANs. WANs, therefore, are usually maintained by public telecommunication companies in countries around the world where WANs are in place. WAN technologies function at the lower three layers of the OSI reference model: the physical layer, the data-link layer, and the network layer.

WANs operate at slower speeds than LANs. Typical data passthrough rates range from 1.5 Mbps to 155 Mbps, and seem like a snail's pace compared to LAN speeds of up to 2 Gbps for a typical LAN network. LANs...