WAN Network (Wide Area Network) Definition

WAN (Wide Area Network) is a computer network covering a large area as an example of a computer network between regions, cities or even countries, or can be defined as well as computer networks require routers and public communication channel.

The Internet is an example of this WAN network if the Wide Area Network already includes intercontinental area then called global information network or the Internet. read : what is the internet

Besides sending packets datagram, the IP network is also known as a connection-oriented packet delivery that is before the package is sent, made the connection setup the logic of the place of origin to the destination by the process control package with a logical connection request that a packet of information to take the same route.

This connection mode called virtual circuit, but unlike the circuit switched network occupying the channel (bandwidth / resources) as a monopoly, the virtual circuit is still in the pattern of use of resources sharing.

In this way a sequence of packets can be guaranteed, fixed level of continuity in real time is not guaranteed, it depends on the capacity and the level of traffic congestion in the network.

With virtual mode circuit allows a group of the organization / company has a private network (such as network PBX) virtual (called IP VPN / Virtual Private Network), or a kind of network PBX (Private Branch Exchange), but the scope of the area is not limited, like the PABX because the network built in IP VPN not physically but logically and tissue formation only when needed so that the scope of the private network IP VPN can cover an area of national and even international.

Other packet switched-based network that has been developed in the USA is a network of ATM (asynchronous transfer mode). The difference with the IP network, ATM network that the overall connection mode using the virtual circuit, while in the IP network, the virtual circuit is merely an option. read : Metropolitan area network definition

Another difference, packets on the ATM network called the cell always remains the 53 octet (byte) which consists of 48 octet payload, 5 octet headers. Whereas in the IP network, the packet size is not fixed. ATM technology has been developed in the United States (not discussed here).

One more thing, that the ATM network is designed based broadband services and can accommodate service VBR (Variable Bit Rate) in addition to CBR (Constant Bit Rate). While the preliminary design of IP-based networks and services Narrow Band CBR.

WAN Network concept
Wide Area Network (WAN) covers a wide geographical area, often covering a country or continent. WAN consists of a collection of machines intended for running application programs the machine-this machine as the host.

The term End System is sometimes also used in the literature. The hosts are connected by a communication subnet, or simply called subnets. Subnet task is to bring a message from the host to the other, as well as phone systems that carry content of the conversation from the speaker to the listener.

By separating the pure communication aspects of a network (subnet) on aspects of the application (host), a complete network design becomes much simpler.

In most of the WAN, the subnet consists of two components, namely cable transmission and switching elements. Transmission cables (also called circuits, channels, or trunk) to move bits from one machine to another.

Switching elements are specialized computers used to connect two or more transmission cables. When the data cable to the receiver, the switching element must choose a wired sender to forward the messages.

Unfortunately there is no standard terminology in calling a computer like this. His name is highly variable called packet switching nodes, intermediates systems, data switching exchange and so on.

As a generic term for computer switching, we will use the term router. But need to know first that there is no consensus in the use of this terminology.

In this model, as shown by the figure below each host is connected to the LAN where there is a router, although in certain circumstances a host can be connected directly to a router.

Set of communication channels and routers (but not the host) will form a subnet.
The term is very important subnet, subnet means the collection was a collection of routers and communication channels that move packets from the host destination host. However, a few years later subnet get more meaning in connection with network addressing.

In most of the WAN, the network consists of a number of many cables or telephone lines that connect a pair of routers. When two routers that do not contain the same cable will communicate, both must communicate indirectly through other routers.

when a packet is sent from a router to another router through an intermediary routers or more, then the packet is received by a router in a complete state, is kept until the output channel to be free, and then forwarded.

Subnet containing such principle is called subnet point-to-point, store-and-forward or packet-switched. Almost all WAN (except those using satellites) have subnet store-and-forward.

In using subnet point-to-point, important design issue is the choice of interconnection topology router.
LAN is usually shaped symmetrical topology, contrary WAN topologies generally erratic.

WAN (Wide Area Network) is a collection of LAN and / or workgroup connected using a modem communication devices and the Internet, from / to the central office and branch offices, as well as between branch offices.

With this network system, the exchange of data between offices can be done quickly and at relatively low cost. This network system can use the existing Internet network, to connect between head office and branch offices or with the Stand Alone PC / Notebook be in another city or country.

WAN network profits.
Central office server can function as a data bank of branches.
Communication between offices can use the E-Mail and Chat.
Document / file is usually sent by fax or postal packet, can be sent via e-mail and transfer files from / to the central office and branch offices with a relatively low cost and in a very quick period of time.

Updating Data Pooling and inter-office data can be done every day at the specified time.
 

4. WAN Network
To connect the WAN network we have to use a special tool that works as a service center, such as VSAT satellite. VSAT is a network or a satellite communications system that consists of a number of remote stations (VSAT terminals) using a parabolic antenna diameter smaller than the satellite communication other, using a or a portion of satellite transponder as a repeater (repeater) with the support of equipment at the station and an earth station main.

WAN is a collection of several LANs are combined into a new network. Here VSAT act as media liaison between a LAN networks. So each LAN network is the terminal station.

WAN covers a wide geographical area, often covering a country or continent. In most of the WAN, the network consists of two components: transmission lines and switching elements.

Transmission wires to move bits from one machine to another. Switching elements are specialized computers used to connect two or more transmission cables.

In the WAN system with VSAT in addition to media servers on each of its LAN network there is still another larger server that are at the Hub station. This server will control the communication between VSAT terminals is below. Servers are located at the terminal station only holds data from workstations underneath.

The working system of the WAN is just like a LAN network only if desired transfer of data from the user terminal VSAT other then the server residing on VSAT terminal will contact the station hub and station hubs will connect to the terminal VSAT desired so that the transfer of the desired data can occur ,

So if the user wants to be contacted only on its own VSAT terminals, the connection to the Hub station is not done.
Besides being used for data transfer VSAT network in WAN configurations can also be used to transfer video and voice.

So workstations terminal should not use a computer, but could use a fax machine or another. This configuration also has a fairly high bit rate for data transmission, in addition to the confidentiality of data is assured anyway.

Although many benefits WAN systems will be ineffective if its use only under the number 100. If you use more than 100 then the system becomes effective and reliable. In the development of the WAN, if the LAN network and a growing number of users around the world are in the system is called the Internet.
 

Insfrakstruktur WAN Network
Such as a LAN (Local Area Network), there are a number of devices that missed the information flow of data within a WAN. Merging these devices will create the WAN infrastructure. These devices are:

1. Router
Router is the increased capacity of the bridge. The router is able to show the route / path (route) and filter the information on different networks. Some routers capable of automatically detecting problems and divert the flow of information from the problem areas.

2. ATM Switch
ATM switches provide high-speed data transfer between the LAN and WAN

3. Modem and CSU / DSU
The modem converts digital and analog signals. At the sender, the modem converts digital signals into a form suitable for transmission technology to pass through analog communication facilities or telephone networks (public telephone line). On the receiver side, the modem converts the signal back into digital format.

CSU / DSU (Channel Service Unit / Data Service Unit)
CSU / DSU as a modem, only CSU / DSU send data in digital format through a digital telephone network. CSU / DSU usually a physical box that is two separate units: CSU or DSU.

4. Communication Server
Communication Server is a dedicated server for users to be able to dial from a remote location so it can be connected to the LAN.

5. Multiplexer
A combination of several multiplexer transmits signals through a circuit (circuit). Multiplexer can transfer multiple data simultaneously (continuous), such as video, sound, text, and others.

6. X.25 / Frame Relay Switches
X.25 and Frame Relay switches connect local data / private over data networks, using digital signals. This unit is equal to the ATM switch, but the data transfer speed is lower than the ATM.

Summary.
WAN (Wide Area Network) is a computer network covering a large area as an example of a computer network between regions, cities or even countries, or can be defined as well as computer networks require routers and public communication channel.

The Internet is an example of this WAN network if the Wide Area Network already includes intercontinental area then called global information network or the Internet.