WAN is the acronym for Wide Area Network (" Wide Area Network "). The concept is used to name the network of computers that extends over a large swath of territory, either through a city, a country or even globally. An example of a WAN network is the Internet itself.
WAN is distinguished from other types of networks, such as LAN (Local Area Networks) or PAN (Personal Area Networks), which have other configurations and scopes. LANs are very popular within businesses or organizations, while PANs operate within the confines of a room or similar spaces.
The WAN network, therefore, involves the interconnection of terminal equipment or other networks that are at great distances from each other. Its infrastructure requires several switching nodes and a significant capacity to support the volume of data traffic.
A switching node is understood to be the device that is responsible for handling the traffic. These teams receive the data through an input line and must choose an output line to forward it.
WAN networks can have various topologies, such as the so-called point-to-point, which consists of the interconnection of nodes through dedicated channels that are always available for connection.
The ring topology, on the other hand, implies the connection of each node to two others, generating a particular pattern that increases the number of possible solutions to possible problems in the connections through a cable.
Other topologies are star (one node becomes the connection center for the rest) and mesh (seeks the interconnection of all nodes, which means a greater ability to overcome failures).
Types of WAN networks
* Switched by message: for this kind of network, the switches are usually computers that have the task of accepting the traffic of the terminals with which it is connected. These teams examine the address found in the header of the messages and can save it to be attended at another time. The messages can be deleted, stored, redirected or answered automatically;
* Switched by packets: the data sent by each user is divided, converted into a series of small parts that, once received by the recipient, are joined to recompose the initial information. It is worth mentioning that each packet navigates the network independently, as if it were individual entities, which lightens traffic and facilitates error correction, since if only one of them fails, it is not necessary to resend the rest;
* Connection-oriented networks: they serve a large number of users, giving each one the feeling of having exclusive resources. This concept is known as a virtual circuit (or virtual channel ), and it belongs to the plane of channel and port multiplexing, that is, the union of a minimum of two information channels in a single transmission medium through a device called multiplexor;
* Non-connection-oriented networks: they are called datagrams and are characterized by going from the free state to the direct data transfer state. It should be noted that this type of network does not perform confirmation, error recovery or flow control for the total set of users; however, each node can access these functions individually. The Internet falls into this category.