Note Repeaters, hubs, and LAN extenders are discussed briefly in this section. A repeater is a physical layer device used to interconnect the media segments of an extended network. A repeater essentially enables a series of cable segments to be treated as a single cable. Repeaters receive signals from one network segment and amplify, retime, and retransmit those signals to another network segment. These actions prevent signal deterioration caused by long cable lengths and large numbers of connected devices.
Repeaters are incapable of performing complex filtering and other traffic processing.
In addition, all electrical signals, including electrical disturbances and other errors, are repeated and amplified. The total number of repeaters and network segments that can be connected is limited due to timing and other issues. Figure 2-6 illustrates a repeater connecting two network segments. A repeater connects two network segments. A hub is a physical-layer device that connects multiple user stations, each via a dedicated cable.