Considering that OpenBSD’s umb(4) and umsm(4) drivers support cards like the Quectel EC25, which comes in a USB variant, I was wondering if it was (at least in theory) possible to make calls using OpenBSD. I know you can get to the internet and send SMS with the smstools port, but what about calling ?
Sorry, I’m a total noob in actual telephony, so can’t evaluate how good those results are.
It just seems that such functionality is supported for the device, and then you probably can do everything via AT commands.
Though it looks like some additional board is required? I don’t know.
Some manual - https://www.manualslib.com/manual/1511434/Quectel-Ec25.html?page=91
Something in Russian, though VoLTE may not be what’s needed (but the general idea may be clear enough with Google Translate) - https://habr.com/ru/articles/696042/ .