Re: Oh well
"you will not get a 50V pots line with fibre, instead at the premises you get an Optical Network Termination unit with a Battery Backup Unit which contains rechargeable cells. These will locally generate the 50V required to operate legacy POTS termination equipment. "
Which is what our local fiber optic connection is. Apparently we've had that long enough now that the last phone bill included a piece about how we might need a new battery soon. I looked and my unit still had a green light.
I hope that it lasts till they upgrade us to gigabit fiber optics which might not happen till 2019. :-(