@Edent Linphone was recently intermittently wiping out my configuration which was a pain to set up again every time. Maybe they fixed it, but I switched to https://www.sipnetic.com/ which has been solid and easier setup. If you are in the US, voip.ms is cheap but has KYC and requires some time investment to setup. Jmp.chat is much easier and a little more expensive at $3/month per number. Other option are here: https://kycnot.me/services#SMS Sipnetic | SIP Client for Android