2. What is a repeater?

A repeater is a device that regenerates the signal transmitted on a cable. Repeaters allow signals to travel beyond the normal cable length limitations. A repeater does not translate or filter packets.

Repeaters have the following characteristics:

• Used to regenerate an existing baseband signal
• Used primarily in a coaxial bus (linear) topology
• Segments connected by a repeater must use the same media access control (MAC) method (e.g., a repeater does can not pass traffic between Ethernet and Token Ring)
• A repeater can pass traffic between different types of media (i.e., coax to fiber optic) if the appropriate interfaces exist
• Segments connected by a repeater must have the same network address
• A repeater does not accelerate or change the signal; it simply regenerates it
• A repeater does not filter packets or limit congestion
• A repeater will pass a broadcast
• A repeater operates at the physical layer of the OSI model
• The basic functionality of a repeater (signal regeneration) can be incorporated into other connectivity devices (e.g., a hub or bridge)

Because a repeater does nothing to filter or limit traffic on the network, it should be viewed primarily as a means of connecting distant workstations, not as a means of adding additional workstations. In other words, repeaters should be used to extend the length of a network but not its density.