Man, you guys really do work with some ancient technology! What kind of equipment do you need an old modem for??
MXP2's and DMS10's mostly, but lot of other equipment is dialup as well. Most of it we access at like 300 baud because if you try to go higher you start to get lot of noise. The DMS10's are also accessible via this telnet type application though but the dialup is a good backup if that application is down.
(random pics I found online)
These boxes monitor voltages, temperature etc.
DMS10: (all the ones I've seen are green though)
DMS100 and 200 are all telnet though, at least that's how we access them. I'm sure there are dialup methods to get to them too.
Our DMS100 in our building has an uptime longer than I've been alive. Old tech but super solid.