REPEATER :

A Repeater is the most basic device on a network. Repeater is device that operate at the physical layer of the OSI model. Repeater has two ports.

A Repeater generates any signal received in on one port and out the other port.

The basic puRepeaterose of Repeater is to extend the distance of something.

The primary puRepeaterose is simply to regenerate a signal received from input and correct the signal to its original state for output i.e repeater takes w weak signal from one segment, regenerates it and passes it to the next segment.

Repeaters are used to connect only same type of media, such as 10 base-2 Thin Ethernate to 10 base -2 thin ethernate, or Token ring twisted pair to Token ring twisted pair.

Repeaters are available in many types.

1- Single port Repeater.

2- Multiport Repeater.

3- Smart Repeater.

4- Optical Repeater.

Single port Repeater operates with two segments that is one segment send signsl to Repeater, it boost and pass to the next signal.

Multiport Repeater connect one segment to another cable segment. Multiport Repeater has one input port and multiple output ports.

Smart Repeater is hybrid device and are very similar to a bridge in functionality. Packet filtering is done by smart Repeater.

Optical Repeaters are Repeaters that operate on optical signal. Most Repeaters in use today are multiport repeaters that are called hubs.

Advantages of Repeater :

1- The least expensive way of expanding a network.

2- They can connect different types of media but they do not have ability ti connect different network architectures such as ethernet an token ring.

3- Passes all traffic in both directions.

Disadvantages of Repeater:

1- The main disadvantage of Repeater is that it passes along everything it detects on the line. If there is noise or distortion the Repeater passes it along with original signal.

2- Not support if network traffic is heavy.

3- Not support to connect different network architectures such as ethernet an token ring.

4- Repeater do not have ability to work beyond the physical layer, which means they do not examine any destination addresses and they do not filter or translate any data.

5- There is a limit to the numbers of Repeaters that can be used to extend a LAN's length and topology. that is ethernet LAN, support maximum five segments interconnected by four Repeaters.