Explain the following devices:

(a) Switch

(b) Repeater

(c) Router

(d) Gateway

(e) NIC

(a) Switch — A switch is a networking device that connects various computing/network devices on a computer network using packet switching to receive and forward data to the destination. When data arrives, the switch extracts the destination address from the data packet and stores it in a table to determine where to send the packet. This allows the switch to send signals to only selected devices instead of broadcasting to all devices. Additionally, a switch can forward multiple packets simultaneously. One of the key features of a switch is that it does not forward noisy or corrupted signals. Instead, it drops such signals and requests the sender to resend them.

(b) Repeater — A repeater is a device that amplifies a signal being transmitted on the network. It is used in long network lines, which exceed the maximum rated distance for a single run. Over distance, the cables connecting a network lose the signal transmitted. If the signal degrades too much, it fails to reach the destination. Or if it does arrive, the degradation of the message makes it useless. Repeaters can be installed along the way to ensure that data packets reach their destination.

(c) Router — A router is a network device that forwards data from one network to another. A router works like a bridge but can handle different protocols. Based on a network road map called a routing table, routers can help ensure that packets are travelling the most efficient paths to their destinations. If a link between two routers fails, the sending router can determine an alternate route to keep traffic moving.

(d) Gateway — A gateway is a network device that connects dissimilar computer networks following different protocols. The gateways act as entry and exit point for a network as they translate communications from one network protocol to the other.

(e) NIC — The network interface card (NIC) is a device that is attached to each of the workstations and the server. It helps the workstation establish the all-important connection with the network and has a unique number identifying it, known as the node address.