Data Only Plan + $0 Google Server + $0 3CX push client voip
My current thoughts on it is that as with current solutions of voip options, it is not as resilient as setting up a Google voice number to receive calls. This is due to the fact that if you are on certain networks like free WIFI locations, the WIFI may be blocking voip ports which will require you to stay on data. My solution is not the best solution, but is one of the many that each person has a choice too.
Push notifications are generally slower than live connection voip clients, but you save on battery in exchange.
Voice mail is answered by an operator which includes needing an interaction to save their own voicemail, this is heaven against bot callers, and hell for non-technical folks who can't understand clear instructions.
If you like to host your own voip mailbox with more features than voip.ms can offer, than this solution is one of the ways.
Please do not abuse the Google Free servers, we would like them to not take them away. They are full fledged computer instances, so you can host other things.
Ask any questions here, I will try my best to address them and update the guide as we all take this journey for a cheaper RFD world.
Fido $15/3GB + voip.ms $1/M + 3cx PBX voip push client $0 + Google Server vps $0 = $16/Month voip solution with no battery drain.