Understanding the network.pdf - Back to Home

Repeaters
The repeater was introduced earlier in the chapter. This device is a signal-amplifier/
transmitter-receiver whose purpose is to amplify and re-clock a transmission signal
between two cable segments (see Figure 1.8).
Figure 1.8. Transmission signal amplification using a
repeater.
Technically, a repeater and a hub are identical. Repeaters are employed in bus
network topologies to connect different network segments together. There are rules
that govern the use of repeaters: If four repeaters are used, the network can be
segmented into five logical segments. Only three of these segments can be used to
terminate computer end stations; the other two must be used for inter-repeater
links (this is known as the 3-4-5 rule). Figure 1.9 illustrates the 3-4-5 rule. This rule
applies only to Ethernet in a bus topology.