Concentrator/Hub

A concentrator is a device that provides a central connection point for cables from workstations, servers, and peripherals. In a star topology, twisted-pair wire is run from each workstation to a central concentrator. Hubs are modular devices into which can be plugged a number of multi-port concentrators. Some concentrators are passive, that is they allow the signal to pass from one computer to another without any change. Most concentrators are active, that is they electrically regenerate the signal as it moves from one device to another. Active concentrators are used like repeaters to extend the length of a network.