If so, who and how is it going? We’re in the mountains, so seeking a way to address spotty coverage. I’m on Liberty Phone, on Crimson.
I’ve had OK experience using VoIP with the voip.ms service on Librem 5 and Crimson. Doesn’t support encrypted calls via TLS/SRTP unfortunately. SIP stack is based on Gnome calls, so you can track most of the issues with it here:
Back in the 2Ks Nat Powning had FWD(Free World Dialup) where you connected a SIP account and the org made $$ by collecting peering price of incoming calls. Google show up and acquired it to make Google Voice and ruined a very nice service.
My three needs are
1-privacy
2-price
3-service quality and reliability that incoming calls route through