I know that there are Tone Tracer test units that allow an RJ45 plug 'tone injector' to be plugged into faceplates, and then at comms room you have what is best described as pen detector .... You can pass it over a bundle of CAT5 cables to identify the correct cable - without terminating or stripping back to the cores. i.e. continuity testing without metallic access. such as:
Anybody come up with a diy solution for one of these.