A hardware device that are used to connect computers, printers, fax machine and other electronic devices to a network are called network devices. These devices transfer data in a fast, secure and correct way over same or different networks.
Network Control devices are:
1. Repeater
2. Hub
3. Switch
4. Bridge
5. Router
6. Gateway
7. Modem
Features of network control device:
Repeater:
It is used to take the distorted, weak and corrupt input signal and regenerate this signal at its output.
It ensures that the signals are not distorted or weak before it reaches the destination.
It recreates the bit pattern of the signal, and puts this regenerated signal back on to the transmission medium
It works in the physical layer with no intelligent function.
Hub:
It is also known as multiport repeater.
It is normally used for connecting stations in a physical star topology.
It is the broadcasting device.
It sends packets to all nodes in the network.
Switch:
It is used to connect multiple computers in which it can direct a transmission to its specific destination. (Unicast the signals).
It is a unicasting device.
It avoids unnecessary network traffic.
It operates in both the physical and the data link layer.
Bridge:
It is a device which connects two or more segment of a network.
A bridge filters data traffic at a network boundary.
Bridges reduces the amount of traffic on a LAN by dividing it into two segments.
It inspects incoming traffic and decides whether to forward or discard it.
It sends packets between two networks of same type.
A bridge operates in both the physical and the data link layer.
Gateway:
It is a node in a computer network, a key stopping point for data on its way to or from other networks.
Gateway is protocol converter.
Gateway enables communication between different network architecture and environments.
It works at all layers of OSI model.
Router:
It is a device that helps in determining the best and shortest path out of the available paths, for a particular transmission.
Routers use logical and physical addressing to connect two or more logically separate networks.
Router read complex network address in packet and efficiently direct packets from one network to another, reducing excessive traffic
It works at Physical, Data-Link and Network Layer of OSI model
It Connect dissimilar networks.
Modem:
Modem works as modulator as well as demodulator.
It is the device used to converts digital signals generated by the computer into analog signals which can be transmitted over a telephone or cable line transforms incoming analog signals into their digital equivalents.
A two way communication is established.