If it’s a phone plug, it should be able to be a modem and able to be used to connect to a dial-in BBS with the right software.
Camas Washington has a BBS with 48 nodes! “DragonLance” must be a local gaming server.
I wonder if this would work, I don’t think my Linux PC has the right software.
OK. I checked the Ubuntu repository and there does appear to be some utilities to dial out.
Modems are dicey at over 28.8 over many VOIP systems; you certainly won’t be getting “x2” speeds over long distance.