An information technology network (IIT network) is a network that is created by connecting two or more computers and other supporting hardware devices through communication channels. It makes it possible for computers to communicate with one another and to share information such as commands and data. It also allows computers to share hardware and software resources.
Computer networks are used for a variety of things.
● It enables you to share resources such as printers, scanners, and other similar devices.
● Users of a network can share expensive software and databases with one another.
● It makes it easier to communicate between computers by allowing them to communicate more easily.
● It enables the transmission of data and information between users over a network.
Computer networks that are widely used include:
● LAN (Local Area Network) is an acronym for Local Area Network (LAN)
● Network for the Metropolitan Area (MAN)
● Wide-Area Network (WAN) (WAN)
Local Area Network (LAN)
In accordance with its name, a local area network is a computer network that operates in a small geographical area, i.e., it connects computers in a small geographical area such as an office, a small company or a small school, or any other organisation. As a result, it only exists within a specific geographical area, such as a home network, an office network, a school network, etc.
Depending on the configuration, a local area network may be either wired or wireless, or a combination of the two. Ethernet cables are commonly used to connect devices in a local area network (LAN). An Ethernet cable provides an interface for connecting multiple devices such as routers, switches, and computers. For example, you can set up a local area network (LAN) at your house, office, or other location by using a single router, a few Ethernet cables, and computers. In this network, one computer may serve as a server, and other computers that are connected to the network may act as clients on behalf of the server.
LAN topologies include the following:
Topology is the arrangement of computers (nodes) in a computer network and is defined as follows: The following are the most common topologies for a local area network:
Topology of the Rings:
Ring topology refers to the fact that the computers are connected in a circular and closed loop, as implied by the name. In this topology, the message only moves in one direction around the ring, from one node to another, and is checked by each node to see if it has a destination address that matches the source address. As a result, the data continues to move until it reaches its destination. There is no client-server relationship between any of the nodes; therefore, they are all equal. A communication failure occurs when one of the nodes fails to transmit data, because the nodes are arranged in a ring and the flow of communication is interrupted.
Topology of the stars:
Using this topology, all of the computers are individually connected to a central node or connection point, which can be any of several types of devices such as a server, hub, router, or switch. This topology has the advantage that if a cable fails, only the affected node will be affected; the rest of the nodes will continue to function normally. All data or messages that are sent from one node to another pass through the central hub before reaching their destination.
This topology is simple to design and implement, and it is also simple to add additional nodes to the central node once it has been established. There is a significant disadvantage to using this topology in that it is prone to bottlenecking or failure at the central connection point, i.e., failure at the central node will have an impact on the entire communication network.
Topology of the bus:
In this configuration, the nodes (computers) are connected together through interface connectors to a single communication line (central cable) that transmits the message in both directions simultaneously. The backbone of the network is a central cable to which all of the nodes are connected and which connects them all together. It is referred to as a bus. In this configuration, the signal travels in both directions to all of the machines until it reaches the machine that will receive it. It is less complicated to set up than other network topologies because it relies on a single central cable to connect all of the nodes together.
The following are some of the advantages of LAN:
- ● It has a faster operating speed than both WAN and MAN networks.
- ● It is less expensive, and it is simple to install and keep up to date.
- ● It perfectly meets the requirements of a specific organisation, such as a workplace, school, or other similar setting.
- ● It can be either wired or wireless, or it can be a combination of the two.
- ● It is more secure than other networks due to the fact that it is a small setup that can be quickly and easily maintained.
LAN’s primary functions are as follows:
- ● File sharing: It enables you to exchange or transfer files from one computer to another computer inside the same local area network. For example, at a bank, it may be used to deliver a file containing the details of a customer’s transactions from the server to the client’s computers.
- ● Additionally, it enables for shared access to printers, file servers, and other similar resources. For example, 10 PCs linked through LAN can share a single printer, file server, fax machine, and other resources.
- ● Computer resources sharing allows clients to use the computing capacity of a server, such as an application server, since some programmes that operate on client computers in a local area network may demand more computational resources.
- ● Mail and message-related services: It enables the sending and receiving of emails between computers connected to a local area network (LAN). It is necessary for you to have a mail server in order to do this.
- ● With the aid of a database server, it is also possible to store and retrieve information.
Metropolitan Area Network (MAN):
A metropolitan area network (MAN) is a high-speed network that spans a wide geographical region, such as a metropolitan city or town. It is built up by joining the local area networks together with the use of routers and local telephone exchange lines, among other things. It might be owned and run by a private corporation, or it can be a service offered by a company such as a local telephone service provider.
MAN is perfect for people who live in a somewhat big geographic region and wish to share data or information with one another. Copper, fibre optics, and microwaves are examples of high-speed carriers or transmission media that are used to deliver rapid communication. Many protocols are routinely used in the MAN, including X.25, Frame Relay, Asynchronous Transfer Mode (ATM), digital subscriber lines, ISDN (Integrated Services Digital Network), ADSL (Asymmetrical Digital Subscriber Line), and others.
The region covered by MAN is bigger than that covered by a LAN, but smaller than that covered by a WAN. Its network stretches from 5 to 50 kilometres in length. Furthermore, it enables uplinks for linking local area networks to wide area networks and the internet. A MAN can be used by an organisation to link all of its LANs, which are situated at its many offices around the city.
Examples of MAN:
- ● Cable TV Network\sTelephone service provides that provide high-speed DSL lines\sIEEE 802.16 or WiMAX
- ● Connected fire stations in a city
- ● Connected branches of a school in a city
Advantages of MAN:
- ● MANs are less expensive to install and maintain than WANs, which means they are less expensive to connect to.
- ● High Data Transfer Speed: The data transfer speed is faster than the WAN.
- ● Local Emails: It is capable of sending local emails in a short period of time.
- ● Access to the Internet: It enables you to share your internet connection with other people, allowing numerous people to have access to high-speed internet at the same time.
- ● MANs are simple to set up since they are made up of many LANs that are connected together.
- ● High Security: It offers greater protection than WAN.
Wide Area Network (WAN):
The Wide Region Network (WAN) covers a broad geographical area. It is not restricted to a single workplace, school, city, or town, and is primarily supported by telephone lines, fibre optic cables, or satellite links to connect users. This kind of communication is mostly utilised by large organisations such as banks and multinational corporations to interact with their branches and consumers all around the world. Despite the fact that it is fundamentally similar to MAN, WAM differs from MAN in terms of its range; for example, MAN covers distances up to 50 kilometres, but WAM covers distances more than 50 kilometres, such as 1000 kilometres or more.
A wide area network (WAN) is comprised of networking equipment such as switches, routers, firewalls, and modems that communicate via the TCP/IP protocol. It is not intended to connect individual computers; rather, it is intended to connect local networks such as LANs and MANs in order to form a larger network. Because it connects numerous LANs and MANs through ISPs, the internet is called the world’s greatest wide area network (WAN).
Typically, public networks like as telephone systems, leased lines, or satellites are used to connect the computers to the wide area network. The users of a wide area network (WAN) do not control the network because it is a big arrangement that connects several computer systems. It is necessary for them to subscribe to a service supplied by a telecommunications operator in order to access this network, though.
Advantages of a WAN:
- ● In the case of a large network range, it encompasses a large geographical area of 2000 km or more, for example, from one country to another.
- ● Data centralization: It enables your different office branches to access and share information by utilising the server located at your headquarters. It eliminates the need for email servers, file servers, and backup servers, among other things.
- ● Receiving up-to-date files and data: It is an excellent platform for businesses that require a live server so that their employees can exchange updated files in seconds.
- ● High bandwidth: It provides significantly more bandwidth than a standard broadband connection. As a result, it can increase the productivity of your company by ensuring that data transfer and communication continue uninterrupted.
- ● The ability to distribute your workload to other locations is a significant benefit of this feature. You can hire employees in a variety of locations around the world and assign them to work from your headquarters.
Examples of WAN:
- ● Internet
- ● US defence department
- ● Stock exchanges network
- ● Railway reservation system
- ● Big Banks’ cash dispensers’ network
- ● Satellite systems