Earlier quoted context omitted.
Lemme know when you get all that.
To be fair, I am more interested in a 4G/5G modem to connect some modular computer. A smart phone is an expensive one. Do you know of a simple modern 4G/5G modem, USB? Only IPv4/IPv6 bridge, I guess you need USB CDC or something for that (NDIS is deprecated)? Any tip?
It's pretty easy to dial the PPP (IP) connection with network manager + modem manager, doing it from scratch with expect scripts is awful, I got that to work once but haven't been able to do it again.
https://www.amazon.com/EXVIST-Dongle-EG25-G-M2M-optimized-Mo...
In theory you can actually make phone calls with it, I've enabled the usb AC device on mine and dialed out with it but haven't actually gotten the loopback set up to work. It's hard to tell if the issue is with Pulseaudio or something in the modem firmware or a regulatory issue or what.
SMS works OOTB with modem manager. MMS works if you're willing to hunt down the MMSD source and build it yourself.