Computer Knowledge: All about Network Devices for Competitive Exams

Comnputer Knowledge: Network Devices

Network devices are required to amplify the signal to restore the original strength of signal and to provide an interface to connect multiple computers in a network. There are many types of network devices used in networking. Some of them are described below.

1) Repeater: A repeater is a device that operates only on the physical layer of OSI model. Repeaters have two ports and can connect two segments of a LAN. It amplifies the fable signals when they are transported over a long distance so that the signal can be as strong as the original signal. A repeater boosts the signal back to its correct level.

2) Gateway: A gateway is an interconnecting device, which joins two different network protocols together. It holds the information from a website temporarily, so that the repeated access to same website or web page could be directed to the proxy server instead of actual web server. Thus helps in reducing the traffic load.The gateway is a node in a network which serves as a proxy server and a firewall system and prevents the unauthorised access. They are also known as protocol converters. It accepts packet formatted for one protocol and converts the formatted packet into another protocol.


3) Hub: Hub is like a repeater with multiple ports used to connect the network channels. It acts as a centralised connection to several computers with the central node or sever. When a hub receives a packet of data at one of its ports from a network channel, it transmits the packet to all of its ports to all other network channel.


4) Switch: Switch forwards a data packet to a specific route by establishing a temporary connection between the source and the destination. It is a small hardware device that joins multiple computer together within one LAN. Switches work on the data link layer of the OSI model. It helps to reduce overall network traffic. There is a vast difference between switch and a hub. A hub forwards each information packet (data) to all the hub ports, while a switch forwards each incoming packet to the specified recipient.

5) Router: Router is a hardware device which is designed to take incoming packets, analyse the packets, moving the packets to another network, converting the packets to another network interface, dropping the packets, directing packets to the appropriate locations etc.

6) Modem: Modem is a device that converts digital signal to analog signal (modulator) at the sender's site and converts back analog signal to digital signal (demoulator) at the receiver's end, in order to make communication possible via telephone lines. A MODEM is always placed between a telephone line and a computer.

7) RJ11 Connector: RJ11 connector is the typical connector used on two pair, four wire handset wiring. RJ means "Registered Jack", the physical connector interface that is most often utilised for handset wire terminals. RJ11 connector wiring comes in two standard assortments -UTP or Unshielded Twisted Pair and flat-satin cable or the untwisted. RJ11 connectors are used to terminate phone lines, and are typically deployed with single line POTS (Plain Old Telephone Services) telephone jacks.