I currently use a Fluke IntelliTone Pro 200 digital toner for tracing data cables on live networks but it bleeds bad. I use a Fluke 620 for testing cables. I recently purchased a Noyafa NF-8209 for 55.00 just to try. Been a phone tech for 43 years, spent a ton of money on Fluke products and this little device helps more than the Fluke. It tones digitally, analog & POE with no bleed, maps pairs, does length, measures POE voltage and here is the best part it will flash the connected port on a live switch and tell you the speed of the port. My co worker purchased the NF-858C which also tests fiber. I don't know about long term but for the amount of time I have had the tester it has already bailed me out on cables that are not marked. Hope that helps...