Therefore, every frame is sent to every output port. Typical office hub. Much larger hubs are typically used to connect larger groups of users. Any repeater or hub may optionally monitor the number of collisions which it observes from each port. A hub may also monitor the state of the transceiver at each 10BT and 10BF Ethernet port.
Receivers monitor the medium to check that idle pulses are received.
If neither an Ethernet frame, or an idle pulse is received within 50-150 ms, the receiver may assume that the cable is not functioning correctly. A disabled port is made active again when 2-10 valid idle pulses are received. This can protect other correctly operating ports from the disruption caused by a faulty NIC, transceiver or hub.