Describe the following networking devices:

(a) Hubs

(b) Repeaters

(c) Routers

(d) Bridges

(e) Gateways

(a) Hubs — Hub is a multi-port and unintelligent network device which simply transfers data from one port of the network to another. It is used to connect several computers together with different ports. When the data packet reaches one port, it is copied to all other ports of the hub without changing the destination address. They can both send as well as receive information but only one task at a time. Hubs can be either active or passive.

(b) Repeaters — A repeater is a device that amplifies a signal transmitted across the network so that the signal is received in the same way as it is sent. It operates only at the physical layer of the OSI model. A repeater is a two-port network device that strengthens the signal intensity and connects two identical networks. A repeater does not change the functionality of the network; instead, it strengthens the signal before it degrades.

(c) Routers — A router is a networking device that forwards data packets from the source machine to the destination machine over a network using the shortest path available. It can handle different protocols. Routers utilize IP addresses to connect local area networks to the Internet. In contrast to a hub or a switch, a router possesses advanced capabilities as it can analyze the data being transmitted over a network, make decisions on how it is packaged, and route it to different computer networks.

(d) Bridges — A bridge is a device that operates at both the physical layer and the data link layer of the OSI model. It connects multiple network segments (LANs) at the data link layer (Layer 2) of the OSI model. It is a smarter hub as it can filter network traffic on the basis of the MAC addresses.

(e) Gateways — A gateway is a network device that connects dissimilar networks. It provides the necessary translation of data received from one network into a format or protocol recognized by devices within another network. A gateway establishes an intelligent connection between a local area network and external networks with completely different structures.