Sim cards and carriers, discussion

[rocket2nfinity]

I've been having trouble connecting my PinePhone (Manjaro) to my AT&T service (4G, Eastern US). A summary of my experiences (currently running Arch, but there was no real difference from Manjaro)...

Using mmcli's --simple-connect option (together with journalctl) shows that the connection almost works, but seems to get rejected eventually (I even see the 4G icon -- the phone is definitely aware of the network), usually with the QMI error "CallFailed".

I tried registering a new sim card in an online form with AT&T, but the web page reports something like "Device Not Found" when I enter my IMEI.

In talking to an AT&T tech for a little while, he suggested that he could manually enter the IMEI. While exploring this option, he noticed that AT&T seems to consider the Quectel Modem (model EG25-G, at least) to be an "internet only" (or "data only") device, that AT&T wouldn't support phone calls and SMS messages on it, and this might be the source of the problem. I didn't want to mess up my existing line, so we ended up not trying the manual IMEI registration.

Disappointing, but maybe informative. Has anyone had a similar experience?

AT&T is using whitelists to determine who gets what access to their network. The Pinephone does support VoLTE. So your best bet would be to use an MVNO that doesn't care and register an android or iphone with the sim if submitting an IMEI is required, then putting that sim in the pinephone.

Adjusting APN settings may also fix the problem.