Network Devices

We know that, there exist a number networking devices. Here we discuss only four important devices among them: Repeater, bridge, router and gateway. These devices are classified as networking devices and inter-networking devices. Inter-networking devices are usually used to connect different local networks into an inter-network

Networking and Internetworking Devices

Each of these four devices interacts with protocols at different layers of the OSI model. Repeaters are deal with electrical component of a signal and therefore active only at the physical layer. Bridges are more active

on data link layer. Routers give links between two separate but same type of LANs and therefore, they active at the network layer. Gateways provide interconnection between entirely different LANs or applications and are active in all of the seven layers of OSI model.

OSI layers and Connecting Devices

Repeater

A repeater is and electronic device that works only on the first layer of the OSI model. Repeaters are also known as regenerators. When a signal passes over a network channel for a long distance it may attenuate that means lost some of its energy. In order to overcome this problem, we use repeaters. A repeater installed on a link receives the signal before it becomes too weak or corrupted, regenerates the signal and puts this copy back to the link. Note that a repeater is not an amplifier.  Repeater does not amplify the signal; it regenerates it.

Advantages

·        Allow to cover a large distance.

·        Connection between various types of media ( optic fiber, coaxial cable) is possible.

Disadvantages

·        Do not provide any congestion handling.

·        Do not work across multiple network architectures.

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