What is LAN? Where is it used? Discuss its uses and advantages.
LAN is the most common type of network. LAN stands for local area network. It covers a small area. Most LANs are used to connect computers in a single building, campus, office or room etc. hundreds or thousands of computers may be connected through LAN. There are many types of LANs. Ethernet is the most common for PCs.
The above figure shows a LAN. All computers are connected to a central node in star topology. The central node is a special device called a network hub. All links are made up of UTP cables. The maximum recommended length of a UTP connection in LAN is 100 meters. No compute should be more than 100 meters away from hub.
All computers in LAN can communicate with each other at a high speed. The speed of communications between any two devices on an Ethernet LAN can be 2 to 1000 millions bits per second (Mbps). LAN can transmit data in a limited distance.
Uses and advantages of LAN
- One copy of a software can be shared by all users in a LAN.
- System resources such as printers can be shared between several people in network.
- It is easy to manage the data stored on a centralized computer in the network.
- The data is more secure from being copied or destroyed.
- Data can be shared by all users using the network.
Explain different components of local area network.
Local area network does not use telephone network. Different components of a local area network are as follows:
- Communication Media
Communication media is used to transfer data from one computer to another computer. Low-cost LANs are connected with twisted wire pair. Many LANs use coaxial or fiber-optic cables. These cables are expensive but provide faster communication. Some LANs use wireless transmission media. It uses infrared or radio waves to connect computers. Wireless networks are easy to setup and maintain. However, they have low transmission rates and limited distance between two communication devices.
- NIC
NIC stands for network interface card. It is also known as network adapter. A network interface card is a device that physically connects each computer to a network. It controls the flow of information between the network and the computer. It is a circuit board that fits in expansion slot on motherboard. Some computers contain built-in network cards.
- Bridge
Bridge is a device that connects two network segments. It si used to connect similar types of networks.
- Router
A router is a device that connects multiple networks using similar or different protocols. It manages the best route between two communication networks. Routers are used when several networks are connected together. They can connect networks of different countries. They transfer data in less time.
- Gateway
Gateway is a device that connects two or more networks with different types of protocols. Two different types of networks require a gateway to communicate with each other. It receives data from one network and converts it according to the protocol of other network. For example, the computers on a LAN require gateway to access the internet.