The only way to connect the SIM number directly is to hack the VoWiFi protocol, but this is not trivial and you still need to install the SIM in the server.
Option 2 - Buy a home SIP2GSM gateway. But it’s quite expensive (by the standards of my region anyway). SMS work with SMPP, calls work too. For goIP I wrote telegram SMS gateway if you interesting: https://github.com/lifespirit/telegram-smpp-bot
Or use SIP providers from your region/operators that support SIP connectivity and then enable full calls redirection. For calls ok.
UPD: or just use VoWiFi from mobile phone. But you need sim slot in phone.
Anyway in all another way you need install asterisk/freeswitch and write config fot it. And linphone client.
The only way to connect the SIM number directly is to hack the VoWiFi protocol, but this is not trivial and you still need to install the SIM in the server.
Option 2 - Buy a home SIP2GSM gateway. But it’s quite expensive (by the standards of my region anyway). SMS work with SMPP, calls work too. For goIP I wrote telegram SMS gateway if you interesting: https://github.com/lifespirit/telegram-smpp-bot
Or use SIP providers from your region/operators that support SIP connectivity and then enable full calls redirection. For calls ok.
UPD: or just use VoWiFi from mobile phone. But you need sim slot in phone.
Anyway in all another way you need install asterisk/freeswitch and write config fot it. And linphone client.