A contractor has removed a wall jack and thrown it away. There is no longer a line number on the network cable. A technician attaches a far end connector and proceeds to several wiring closets to…

A toner probe kit consists of a tone generator attached to one end of the cable and an inductive amplifier (probe) used to detect the tone along the cable's path and at patch panel ports. This allows a technician to positively identify an unlabeled cable run through walls, ceilings, or across patch panels without needing a line number.

A loopback plug redirects outgoing signals back to the receiver on the same port to test whether an interface is functioning, and cannot identify or trace a cable's physical path.

A cable tester verifies that all wire pairs in a cable are correctly terminated and continuous, but it cannot locate or trace where an unknown cable terminates in a wiring closet.

A multimeter measures voltage, resistance, and current for electrical diagnostics, but lacks the ability to identify or trace a specific network cable among many.