Network Devices

Network devices are electronic devices which are required for communication and interaction between nodes on a computer network. Specifically, they mediate data transmission in a computer network.

Hubs and Switches

Both Hubs and Switches are exchange node at the logical center of an Ethernet network. Each network node connects to hub or switch through a cable plugged into a socket called a port.

Hub

A hub is a device used to connects number of nodes together to make a LAN. Hub is also a typical center part of Star and Hybrid Topologies. When hub receives a data packet it sends it to all connected nodes in that network. Each node then either accept it if address is same or ignore it if packet is addressed to some other node. Because of this hubs are not very secure and also cannot transfer multiple packets simultaneously.

Switch

Switch are more intelligent device as compare to Hub. When switch receives a data packet, instead of sending it to all connected nodes, it read the address of packet and set up and logical link between source and destination, without interrupting other links in the network. Because of this, switches are more secure than hub and also can transfer multiple packets simultaneously by setting up multiple direct link between source and destination.

Modem

A modem is a network device that both modulates and demodulates analog signals to digital information. Modems accomplish encoding and decoding simultaneously and, for this reason, the term modem is a combination of "modulate" and "demodulate."

The most common use for modems is for both sending and receiving of the digital information between personal computers. This information used to be transmitted over telephone lines to a digital format for a computer to read.

Router

A router is a device that communicates between the internet and the devices in your home that connect to the internet. As its name implies, it “routes” traffic between the devices and the internet. A router has multiple interfaces and receives data packets through them. It evaluates the network addresses of the incoming packets and decides which interface to forward the packet to.

Different types of routers

• Wired routers: A wired router connects directly to computers through wired connections. They usually have a port that connects to the modem to communicate with the internet. Another port or ports allows the wired router to connect to computers and other devices to distribute information.
• Wireless routers: A wireless router connects directly to a modem by a cable. This allows it to receive information from and transmit information to the internet. The router then creates and communicates with your home Wi-Fi network using built-in antennas. As a result, all of the devices on your home network have internet access.

Bridge

Bridge is a network device used for interconnecting two or more LANs working on the same protocol to form a larger LAN. The process of aggregating networks is called network bridging.

Bridge devices work at the data link layer of the Open System Interconnect (OSI) model, connecting two different networks together and providing communication between them. Bridges are similar to repeaters and hubs in that they broadcast data to every node. However, bridges maintain the media access control (MAC) address table as soon as they discover new segments, so subsequent transmissions are sent to only to the desired recipient.

Bridges are also known as Layer 2 switches.

Repeater

A repeater is a network device that receives a signal and retransmits it. It receives the signal before it becomes too weak or corrupted. It regenerates the bit and forwards the refreshed signal. A repeater operates at the physical layer.

A repeater is implemented in computer networks to expand the coverage area of the network by repropagate a weak signal.

Repeaters are also known as signal boosters.