Patching a PSTN connection through pre-existing CAT5
I'll try to make this simple, as I have a habit of making things more complicated than they should be!
I need to make a Master PSTN socket available in a different room of our building to where the main socket currently is. There is CAT5 cabling between the two locations, so I figured I'd use that. I've looked into the available adaptors (this sort of thing from Amazon), but they come in 'primary' and 'secondary' versions. I understand that every domestic PSTN line has a master socket and all others are secondary to that, but I can't figure out which of these adaptors is appropriate in my situation. So, here's my question:
When the PSTN socket I'm connecting to is already a Primary/Master socket (i.e. it has the capacitor etc required for making a telephone ring), should I use a primary or secondary type adaptor to extend it's connection?
By my reckoning, I need a secondary type adaptor (given that the master PSTN socket already has the required electronics). I would need a primary type adaptor if I was sending the PSTN line over CAT5 before it reached the initial 'Master' socket. Am I correct?