Ok it's just a theoretical question I am not actually going to get rid of my broadband connection.
I am currently with Slingshot UFB (broadband + phone)
I understand fibre installation is a one way street and I can't go back to copper anymore (although the line is still there.)
What if I sell the house and new owner only wants a landline? Can Slingshot (or any telco in that matter) deliver VOIP only over fibre?