Over on the Fediverse, Mike Sheward shared some words of network engineering wisdom :

i’ve said it before and i’ll say it again; you’re not a network engineer unless you’ve moved a ceiling tile to trace a cable and had a small netgear switch fall on your head

You might wonder how on earth you wind up with little switches stuck in the ceiling (well, above the ceiling). At work, we've kind of been in this situation ourselves , so I can tell you our situation, or more exactly the university's situation.

As you might expect, the university has any number of old buildings. When many of these buildings were built or, more likely, renovated for twisted pair Ethernet wiring, wiring and ports and so on were expensive and no one really foresaw how pervasive and popular this 'computer networking' thing would get. The result is that these buildings were often initially wired for a much lower port density than they turned out to need later. In the era of 100 MBit networking, this lead to some significant hacks such as Ethernet splitters , but these hacks can't be used if you need 1G Ethernet (and in practice you do these days).

Renovating a building (or part of it) to add more network wiring and more network ports in the proper, conventional way is expensive and perhaps disruptive (you have to move people out of their existing space to take it apart to run the new wiring through it and so on). At the university, typically this only happens as part of a general renovation , when they have to take the space apart anyway. People have learned to run lots of wiring at that point; the actual Cat-6A cables and network jacks are inexpensive these days compared to the labor costs to pull cable bundles, and you can terminate cables in a wiring patch panel without hooking them up to switches.

If you can't afford to run new wiring, arguably the proper way to solve this is with a collection of small fanless switches in office areas (you want fanless switches because people often object to switch fan noise). However, that's a switch-intensive setup no matter how you arrange it, and it involves leaving switches lying around in the relative open where various things can happen to them. If you don't want to do this, an alternate way of dealing with the problem is to move the necessary switch or switches out of sight by putting them above a false ceiling. Sometimes you can get away with a small fanless switch; at other times, you may need a somewhat bigger and noisier switch, which will be muffled by being on the other side of the ceiling tiles. If you need a few more network wires to support this, there's often ways to run your own network cables yourself back to some area you can put a distribution switch.

(Then you can run cables from the ceiling switch, over to the side of the wall, down the wall (often in a stick-on plastic conduit), and to a network port box that you've used adhesive to stick on the wall. Done carefully this can look almost like real wiring.)

This has some obvious drawbacks and also some less obvious ones. In particular, you or the people who come after you often aren't going to remember that you have those switches up there. When one of them eventually stops working, this can lead to exciting trouble-shooting sessions, and if anyone ever takes the wrong ceiling tiles off, this can result in things falling on them, or at least the sudden appearance of a switch that's being held aloft in mid-air only by the power and network cables connected to it. This can be especially fun if who's in the space has changed since it was wired up with the ceiling switches.

(In theory this can be well documented and the ceiling tile with a switch on the other side can be clearly marked and all of that. In practice my impression is that this is often done somewhat quietly and without such things, partly because some parts of the university want you to do your network wiring properly even if it requires money, time, and so on your department doesn't have.)