The provider I use is https://voip.ms https://voip.ms The UI takes some getting used to but the service is cheap and works great. Similar to how I did it, you'

The provider I use is https://voip.ms https://voip.ms The UI takes some getting used to but the service is cheap and works great. Similar to how I did it, you'd need an ATA box to provide analog service to the phone, and it would talk to your provider over SIP/RTP. Another option would be a self-hosted PBX box. Asterisk [1] is the tried and true open-source option, but it does have some sharp edges. 3CX [2] is another option, but it's proprietary and has some limitations. Either way, you would need a provider to give you the 'SIP Trunk' (phone number etc). I think Twilio [3] is the best option for this, but I've been using a hosted service for a while so I don't have much recent experience with this and can't vouch for costs/functionality. --- [1] https://www.asterisk.org/ https://www.asterisk.org/ [2] https://www.3cx.com/free-pbx-edition/ https://www.3cx.com/free-pbx-edition/ [3] https://www.twilio.com/sip-trunking https://www.twilio.com/sip-trunking