Vocational Training Course-2008

3COMPONENTS OF A NETWORK

Different types of physical components are involved that builds a LAN/WAN computer network. The major components are hubs, NIC adapters, network cables, routers, switches, modems and gateway. Following is the basic overview of each of the major component of a computer network.

Servers

Network servers are computers that provide different services to a computer network such as logon authentication, internet access, disk space, printing access, CD/DVD-ROM access, database access, antivirus and other software application updation etc. The specialized server operating systems are Windows 2000 Serve, Windows 2003 Server, Linux and Sun Solaris. In the Windows 2000/2003 server, active directory holds the users and network computer information.

Cabling

There are different types of network cables are involved in a compute network such as coaxial cable, Ethernet cable UTP/STP and fiber optic cable. The most commonly used cable in a local area network is UTP/STP (Unshielded twisted pair/shielded twisted pair). However fiber optic is currently replacing all the traditional cables and is being widely used in LAN and WAN networks. Data travels at the speed of light through the fiber optic cables thus fiber optic is a fastest data carrier in the computer networks.

LAN cards

LAN cards, NIC or network adapters are the essential physical parts of any computer network. Every computer in a network requires a LAN card to get connected with the other computers in the network. Every LAN card is assigned a unique IP address for computer’s identification on the network. Wireless LAN cards are used in the wireless LAN.

Switch/Hub

Hub or switch is a centralized device and both devices almost play the same function i.e. every computer in a network (in star and mesh topology) is directly connected

AIR GWALIOR C.P.Harikumar-2008

Vocational Training Course-2008

with the hub or switch. The major difference in hub and switch is that when data arrives at hub it broadcasts it to the every the computer in a network and only the destined computer accept the data however the in case of switch, data is only transferred to the destined computer and not to the all computers. Switch provides more data transfer speed as compared to the hub. In the advanced switches, a switching table is maintained, which has the database of IP addresses and MAC address of every computer.

Router

The basic function of the router is to route the traffic (data) to its destination based on the IP address. Router is a most important network communication device in LAN and especially in WAN and the whole communication system of the internet is based on the routers. Router is a key component is WAN. Like in the advance switches, Router maintains the routing table, which contains the IP address of the source and destination routers. With the help of the routing table, a route finds the best shortest possible path of the destination. Routing tables are continually updated and this updatation is propagated in all the connected routers.

Antenna

Antennas are the part of a wireless computer network for boosting the signals for adapters, access points, and bridge equipments. Antennas also provide the building to building wireless connectivity and some of the types of antennas are directional antenna, video antennas, yagi antennas, wireless communication antennas, omni-directional antennas, and base station antennas.

Modems

Modem is a network device that performs two functions modulation and demodulation i.e. it converts the digital data into the analog signals and the analog data into digital.

Gateway

A network gateway is a computer, software or device that is directly connected with the external network i.e. internet. All the incoming and outgoing traffic of a network passes through the gateway. Gateway computers are kept very secure as the can be attacked directly through the internet and in case of any security holes and weaknesses in the gateway computer, all the computers in a network can be attacked.

Backbone

A backbone is a main line of wire such as fiber optic cable that connects two or more big networks such as ISPs.

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AIR GWALIOR C.P.Harikumar-2008