A WAN, or Wide Area Network, is a computer network that connects two or more LANs, or Local Area Networks while covering a wide geographic area. A WAN of this type would connect several offices of the same enterprise located in the same city, but not physically adjacent to one another. Each individual office has its own LAN, but the enterprise requires that each LAN appear to be a transparent part of one shared network, with no restrictions, gateways or delays. This kind of WAN allows its multiple sub-networks to share the resources, data and applications centrally available with complete transparency, regardless of location or transport method.
A WAN can interconnect several types of smaller networks, such as Metro Area Networks (MANs), Campus Area Networks (CANs), and even Wireless Wide Area Networks (WWANs), crossing states and even countries. The world’s most popular – and largest – WAN, of course, is the Internet – which offers the myth of free WAN transport technology for all. But as every episode of ‘Ice Road Truckers’ shows, calling something a road and sending mission-critical traffic down it doesn’t make it trues. WAN transport is more complex and demanding than that. From the days of X.25, to private lines, to Frame Relay, to ATM, to IP-VPN, to today’s Carrier Ethernet, successive transport technologies have become the WAN traffic ‘road’ of choice – until the next big thing bursts on the scene.
Carrier Ethernet or Ethernet, offering speeds up to 100 Gigabits where available, is currently the ne plus ultra of WAN transport technology, and its share of the transport market is growing exponentially. As a WAN transport, Ethernet enjoys several transformative advantages over its predecessors, starting with profound ease-of-use due to its origination as a LAN technology. Further, there are several ‘models’ of Ethernet on the market, ranging from the ‘entry-level’ Ethernet Over Copper to the home, to the ‘luxury model’ Ethernet Over Optical Fiber found in Metro Area Networks. Finally, Ethernet offers simple and fast scalability in both size and bandwidth; security, optimization, and performance features; and it’s extremely cost-effective in comparison to all previous options. The one possible exception, IP-VPN, unfortunately, is not much of an alternative, because the public Internet is neither secure, nor controllable. Carrier Ethernet has become the standard for business WAN transport for the prioritization of traffic, bandwidth guarantees, and critical applications features it offers – lower latency, higher throughput, and high availability – inexpensively, easily and quickly.