Patch Panel Mystery

CitationJetA · July 14, 2023

Hello all,

I managed to get access to the IT room of my floor in my apartment building, and I have a question about the patch panel (photo attached). Every unit has 2 CAT6 cables run to them, one of which is labelled "D" which is obviously data. The other is either labelled "V" or "L." For units with "V" (including mine) the port is unpopulated, and I'm thinking this is for a voice line. My question is what could the "L" mean in this context? All of the "L" ports are connected back to a UniFi switch, which indicates a link is established at 100mbps and no PoE. Any guesses?

Needfuldoer · July 14, 2023

Do you know what's at the other end of those patches?

I agree that D probably means Data and V probably means Voice. You'll have to see how those voice lines are terminated; if they're Cat6 runs that are properly terminated to 8P8Cs at each end, there's no reason they can't be used for data too. (That tells me they were either pulled as 1:1 replacements for Cat3 voice lines, or you inherited infrastructure from someone stuck in the 90s.)

And please unplug 1005L and 1006L, then plug them back in so that fiber isn't woven between them.

EDIT: And what's up with that numbering? The port numbers aren't in order! Are they punched down in order of where they land in the building? I hope you've got a map of which runs go where, otherwise you might have to do some cable tracing with a Fox & Hound or the good old fashioned scream test.

Edited July 14, 2023 by Needfuldoer
The mess you inherited is upsetting me the more I look at it :(

CitationJetA · July 16, 2023

Thank you for the reply!

I don't know what's on the other end of the patches, I just wanted to get the community's best guess as to what they might be. To be clear, I'm only a resident of the apartment complex, I'm not acting in a sysadmin capacity for the building but I agree it's quite a mess. This is actually a new building, completed in 2020.

Also, contrary to my original post, the UniFi switch is indeed providing PoE to whatever's on the other end. This complex has a building-wide z-wave network for smart lighting and thermostats, and my best guess is that "L" stands for "lights" and there are Z-wave base stations on the other end. The forum post was totally out of curiosity, since I don't have whatever it is in my apartment, I'm a "V" unit.