We have a cranky drop in the main office that is used by the receptionist for her phone. The drop has no designation so, by eye, there is no way to match it up with the port to which it is connected in the IDF. There is a thingamajigger that sends a signal through the cable so that you can ID the port. I can’t remember its name. “thingamajigger”, apparently, isn’t an exact enough designation. LOL
Who can give this name?
Port Detector or Port Flasher?
Something like this?
More generically, a cable tracer. There are several variations, but most I’ve worked with use a device plugged into the wall port and another device that is either plugged into candidate ports at the other end until the first device is detected, or touching cables with a probe until the first device’s signal is detected (tone tracer).
Awesome! I actually used your link and bought one! Thanks! 
I knew this wouldn’t take long. LOL
This is the one I use at work. It’s more expensive but it can send a tone while the line is connected to a network switch. Some of the cheaper tone & probe sets can’t do that.
Thanks. If the one I ordered doesn’t work (cheaper model), my boss will have to spring for this one. I’m not THAT generous. LOL
To be clear. I’m not endorsing it, it was the first one I saw when I searched for port flasher.
I’ve played with those toner devices. Not ideal, but work for lost of things. The one I used had alligator clips, so you could use it for any wiring.(more often, telephone wires.) it was handy for tracing routes, since you could wave it along a bundle of wires and tell whether the wire followed that path. For network cables, it was more about having someone at the other end near the computer and calling out (or cellphone) “plug it in… take it out… plug it in… out…” and you could see what port on the switch was going on-off-on-off in time to these actions.
Sometimes I get frustrated and just yank on the wire in hopes that the other end will make itself known. It doesn’t usually work.
Just a few weeks ago I was at work trying to find two ends of an ethernet cable and was driving myself crazy. I finally climbed up on a checkout counter so I could follow the wire with my hands through an overhead area (across the top of an I-beam) that I couldn’t see. Long story short, for unrelated reasons, half of this cable was a different color.
Turns out taking a black ethernet cable and spray painting half of it white makes it real PITA to trace. The ‘yank on one end’ method yielded very confusing results.