It's probably worth distinguishing between "POTS" and "PSTN" since they technically mean different things and they potentially describe different technologies.
Most people use POTS to basically describe (in US terms) a a phone line that's entirely analog from the local central office switch (a DMS-100 or ESS5, or similar) to your house. PSTN refers more widely to the entire public switched telephone system, and I'd argue, to more modern implementations of "home phone line" which basically involve things like DOCSIS cable modems that have analog phone adapters in them, or DSL modems that have analog phone adapters in them (your cableco and AT&T U-Verse, respectively) or a copper DSL line terminated at a DSLAM which itself can generate dial tone and has an analog telephone adapter in it (these exist but IDK who is using them yet) or a fiber version of the same (almost any fiber line, some are IP-based up to the home, some are TDM over the fiber, but the distinction sometimes matters.)
And really, to put a finer point on it, neither of them is being asked for here. What OP really wants is a line simulator so they can more easily dial one computer from the next, or a PBX so they can do the same but either multiple times at once or without having to re-wire things.
I had dial-up until 2006, so I associate it with newer computers than some. Like, if I had a PBX set up as such, I'd probably get a modem for my Beige G3 or for an iMac G3 and connect it to my LAN that way. It would be overly complicated and arguably it would be bad since there's really nothing preventing me from buying that length of normal Ethernet cable and putting a gigabit switch in my room and using the network that way, but it would hit an oddly specific nostalgia button for me, especially with something like hotline or the 68kMLA IRC channel (and wider Internet, so I can look at system7today) on the other end.
Most people use POTS to basically describe (in US terms) a a phone line that's entirely analog from the local central office switch (a DMS-100 or ESS5, or similar) to your house. PSTN refers more widely to the entire public switched telephone system, and I'd argue, to more modern implementations of "home phone line" which basically involve things like DOCSIS cable modems that have analog phone adapters in them, or DSL modems that have analog phone adapters in them (your cableco and AT&T U-Verse, respectively) or a copper DSL line terminated at a DSLAM which itself can generate dial tone and has an analog telephone adapter in it (these exist but IDK who is using them yet) or a fiber version of the same (almost any fiber line, some are IP-based up to the home, some are TDM over the fiber, but the distinction sometimes matters.)
And really, to put a finer point on it, neither of them is being asked for here. What OP really wants is a line simulator so they can more easily dial one computer from the next, or a PBX so they can do the same but either multiple times at once or without having to re-wire things.
I had dial-up until 2006, so I associate it with newer computers than some. Like, if I had a PBX set up as such, I'd probably get a modem for my Beige G3 or for an iMac G3 and connect it to my LAN that way. It would be overly complicated and arguably it would be bad since there's really nothing preventing me from buying that length of normal Ethernet cable and putting a gigabit switch in my room and using the network that way, but it would hit an oddly specific nostalgia button for me, especially with something like hotline or the 68kMLA IRC channel (and wider Internet, so I can look at system7today) on the other end.



