I'm thinking of getting fibre, however my master socket is located in the living room and I like my router upstairs. I have two telephone ext sockets, the router currently plugs into one upstairs. I'm wondering if I can convert the existing telephone ext to ethernet, change the master socket to one that has an ethernet port, link out the middle telephone ext and blank it off, change the end extension to an ethernet port for the router. Then when I get fibre, connect the ethernet cable from the modem to the master socket face plate, then upstairs connect the ethernet cable to the modem. I need to check and see if the telephone wiring is Cat5 or not, its a relatively new house.
You could do what you want but it will require Ethernet cable either already being where you want it to start and finish or you will need to run the cable.
Phone cable can not be used as a substitute for Ethernet.
Phone wiring is normally CW1308 but developer may have used Cat5e cable but more likely something cheap and nasty.
Why don't you just discuss with the install engineer to have the ONT fitted upstairs?
I could speak to the engineer but i don't want any cables running around the outside of hosue or drilling through walls, the existing telephone cable is cat 5e. Is there any bt master sockets that have an ethernet port?
No.
If you are getting fibre you will no longer need a master socket, just change the faceplate for an RJ45 faceplate once the copper line is no longer required.
Just Google "RJ45 faceplate". Even if you wanted to retain the phone sockets for telephony by patching into the SH2, you won't have enough wires as Gigabit ethernet needs all eight.