To get a wired Ethernet connection onto the first floor , the phone master socket doesn’t really matter, the cable than you run to the first floor ( as already stated ) needs to be a Suitable CAT5 or better type cable and would ideally be terminated on its own RJ45 socket next the router , you use a short ‘Ethernet’ cable to connect one of the LAN ports of the router to this RJ45 ‘data’ socket….upstairs, the other end of the CAT cable is also terminated on an RJ45 socket close to where the PC is going to be sited, and another short Ethernet cable plugs into it and the LAN socket of the PC….your original post suggested you wanted a ‘line’ which usually means a telephone line upstairs , that why the master phone socket etc was mentioned.
You updated this thread yourself while I was entering this , yes , what you have posted is ideal
