WAN Connections

WAN:

Which is simply defined as Wide Area Network it is a data communication network which operates beyond the geographical scope of Local Area Network (LAN).

WAN requires a carrier to contact such as a local service provider, or a carrier, a cable or telephone company. The service is connected throughout their organizations and to each others of various locations which are in remote users. Mostly carrier’s different variants of traffic types such as video, data, and voice.

There are three major characteristics of WANs:

• Various services of carriers are used in WANs such as network providers, cable companies, satellite systems, telephone companies.

• To provide access for large bandwidth over geographical areas WANs use serial connection of various different types.

• WANs are mostly and commonly used for connection between the devices which are separated by wide geographical areas.

                                              

Basically LAN and WAN are differed in two main ways in area and in ownership:

	WANs	LANs
In Area	They are wide geographic area	In single building or a campus covering small geographical area
In Ownership	The subscription is maintained by outside service provider	In these the connections are owned by organization and itself.

 

Access In WAN and the Reference Model Of OSI:

With the relation between OSI reference model the WANs can work. And their main function focuses are on layers of 1 and 2. They access both data link layer requirements and physical layer delivery methods, which includes encapsulation, flow control, and physical addressing. Number of recognized authorities which include the ISO, the Electronics Industry Alliance (EIA), the Telecommunications Industry Association (TIA) theses define WAN and their standards.

In the physical layer which is OSI layer 1 protocols describes the provision of operational, electrical, mechanical, and various functional connections to the communications service provider.

 And in the data link layer which is OSI layer 2 protocols define the data encapsulation which was transformed to a remote location and the various mechanisms which for transferring the data in resulting frames. Different variants of technologies are used basically as Frame Relay and ATM. The following table shows the WAN technologies which uses the OSI reference model.

                                                   

WANs Devices:

In a WAN several various devices are operate on the physical layer. The following are some of them which uses the WAN access:

• Routers: Which are mostly used. They provide WAN access and internetworking interface ports.

• Communication servers: In these they concentrate on dial-in and dial-out user communication.

• Modems or digital service units (DSU)/channel service units (CSU): Modems are used to transform the digital signal of the sending device to the analog format and for the digital types of lines a DSU and a CSU are to be required. And which the two are combined into a single piece of device, called as the DSU/CSU which can also be built into the interface card in the router.

• Networking Devices of WANs: Devices such as core routers, public switched telephone network (PSTN), ATM switches and Frame relay switches are also mostly used in the cloud storage to support access services.