I've seen a news story today that in the UK they are planning to switch off PSTN landlines from 2025. BBC News story
I know Comfort has a GSM backup option (although mine still has bugs/issues during AC power failures - but that's another thread) but will there be any new modules or way of Comfort still working over VOIP landlines in four years time? Or is there already a way to support this?
VOiP lines are not suited for Control by DTMF. This is because the technology is meant for voice which can tolerate delays in the signal frequenmcies. DTMF may not work well on these lines. GSM is still the better alternative