Wide area network

A Wide Area Network (WAN) is a computer network that includes a wide area (ie, is communication across borders, the metropolitan regional or national [1 as a network link]). Less formally, a van is a network that uses routers and public communications links. Personal Area Network (PAN), Local Area Networks (LANS), campus area network (box), or metropolitan area network (person), which is common as a room, building, campus or specific metropolitan area is limited to contrast with ( As a city) respectively. And a van more than the best known example is the Internet. A van a data communications network covering a relatively wide geographical area, namely (from one country to another city and another one for the country) and often common carrier transmission, uses features such as provided by telephone companies. Generally, at least party technologies van OSI reference model, three layers: physical layer, data link layer and network layer .