My current house has all the phone line wiring done up nicely (RJ11 socket in the wall, etc), upstairs and downstairs.

Since I'm terminating my streamyx and upgrading to unifi soon, I wonder if I can re-use the same telephone lines for the same phones in my house?

Is it possible to plug in the phone cable from the BTU to the phone jack in the wall, and then all the phones in my house will work?

your house is landed right?
if yes, technician will drect pull the fiber optic for you.

thanks.

yes, they will pull fiber for me. then the fiber will go to the BTU. but my question is, my BTU is going to be upstairs. i have a phone jack in my wall. can i connect the BTU to the phone jack in my wall and my downstairs phones will have line as well?

im not sure. is it can from btu (voip 1) connect to phone jack, and from phone jack to dect phone

It will work, im using that currently.
What you will need to do is wired in your downstairs phonebox so that from your room it will goes to other room.

BTU-->your wall jack--> your phone box --> wire it to other room cable..

Ah ok, got it. Thanks!

Yes, from btu (voip) to phone jack, phone jack connect to dect phone downstairs.

rockylabu: yes, my house is already wired. so i'll give it a try!

thanks for the reply guys.