What is a WAN

The establishment of a wide range of computer communication networks. A wide range refers to the geographical scope, can surpass a city, a country even to the global. Therefore, the requirement of communication is high and the complexity is high. Wide Area Network English full name is wide area network, referred to as WAN, is a cross-regional data communication network, usually contains a country or region.

In practical applications, wide area networks can be connected to local area networks (LANs), that is, a LAN can be a terminal system of WAN.

The organization of wide area networks must be carried out according to a certain network architecture and corresponding protocols, in order to realize the interconnection of different systems and work together.

A wide area network typically consists of two or more LANs. Computers often use the equipment provided by telecommunications carriers as information transmission platforms, such as through a public network, such as a telephone network, connected to a WAN, or through a dedicated line or satellite connection. The Internet is currently the largest WAN.

In contrast to the OSI (open System Interconnect, open Systems Interconnection) Reference model, the WAN technology is mainly located at the bottom of the 3 levels, namely: physical layer, Data link layer and network layer. When a WAN exceeds a "local" network, it will enter the scope of the wide area network. Or we can see that, "wide-area" network so that the "local area" network connected to become a larger network. A country should be regarded as a "wide area" network, and beyond this scope, many national "wide-area" network together, forming the current global "Internet". The development of local area network, the combination of wide area and wide area, eventually become the global "Internet"!