A structured cabling system has two patch panels each having a plurality of jacks. Adjacent each jack is a Light-Emitting Diode (LED) which can be illuminated in response to a signal from a processor to identify the associated jack. The processor illuminates each LED in a sequence to identify the connections which should be made between the jacks, so that a first LED is illuminated, and once, the presence of a plug of a patch cable within the associated jack is detected, that LED is deactivated and a second LED is illuminated to identify the jack to which the plug on the other end of the patch cable should be connected. Once the presence of the plug in the second jack is detected, a continuity check is carried out between the two jacks before moving on to the next jack.