On Mon, 22 Jul 2019 18:22:06 +0100, Davidm wrote:

Well, I would advise you to have at least one old fashioned line
powered phone on the truecall for when you get a power cut.
truecall
defaults to straight through, so this should work fine.

Yes I have, it's not normally connected, but nearby in a drawer with a
torch. Plus of course we have mobiles.

Mobile phone cell sites require mains, very few sites have battery
backup beyond a few hours, if that. Almost none have generators.
Expecting the mobile phone network(s) to work under power fail
conditions is a bit risky.

--
Cheers
Dave.