WAN A Wide Area Network (Wide Area Network or WAN, in English) is a type of computer network capable of covering distances from about 100km to about 1000 km, giving the service to a country or continent. An example of this type would RedIRIS network, Internet or any network in which not a single building in all its members (about the distance is no argument possible). Many WANs are built by and for a particular organization or company and are for private use, others are built by Internet service providers (ISPs) to provide connectivity to their customers. Today the Internet provides high speed WAN, and the need for private networks WAN has been drastically reduced while using VPN encryption and other techniques to make that network dedicated continually rise. Typically the WAN is a network point to point, ie packet switched network. WAN networks may use satellite communication systems or radio. It was the advent of laptops and PDAs that brought the concept of wireless networks.A wide area network or WAN (Wide Area Network) is spread over a large geographic area, sometimes a country or continent, and its main function is geared towards networking and terminal equipment are located at large distances between yes. For this they have an infrastructure based on powerful switching nodes that perform the interconnection of these elements, which also flow a significant amount of information continuously. Corey S. Ribotsky For this reason also said to WAN networks are public, because the information traffic flowing through them comes from different places, used by many users from different countries around the world to transmit information from one place to another. Unlike LANs (stands for "local area network", ie "local area network), the moving speed at which the data WAN is usually lower than can be achieved in networks LAN.In addition, networks are private LAN because their use is normally restricted to users who are members of a company or institution, which designed the network. The WAN network infrastructure composed, in addition to the switching nodes, transmission lines of high performance, characterized by their great speed and bandwidth in most cases. The transmission lines (also called "channels", "channels" or "trunk") move information between different nodes on the network. The switching elements are also high performance devices because they must be able to handle the amount of traffic flowing through them. In general, these devices come to them by a data input line, and this should take care to choose a starting line to forward them. Then, in Figure 1, displays an overview of the structure could be a WAN.In it, each host is connected to a LAN, which in turn connects to one of the switching nodes of WAN. This node should be responsible for routing the information to the destination for which it is addressed. Before addressing the next topic, it is necessary to clarify the terms switching, which we could define the way in which the nodes or elements ensure interconnection of two end systems interconnected to exchange information.