T-Mobile registration trouble (USA)

Aleksander Morgado aleksandermj at chromium.org
Fri Oct 21 08:10:52 UTC 2022


> After something of a hiatus induced by work priorities, I am back to my
> project that uses ModemManager and a "glue" program to tell it to
> connect. Code that was working back in July isn't working, and our IT
> folks gave us new SIMs from T-Mobile. Here in the USA, T-Mobile has
> instituted a requirement that a SIM be bound to a specific IMEI. I am
> using the ModemSimple.connect call to connect, and I keep getting a timeout.
> Using mmcli, I run this command and also get a timeout:
> $ mmcli -m 0 --simple-connect='apn=fast.t-mobile.com,ip-type=ipv4v6'
> My boss is getting the same thing with a different modem and SIM. Both
> SIMs have allegedly been paired with the IMEI in T-Mobile's records.
> Does anyone know if simple-connect still works with T-Mobile in the USA?

Yes, it works. There are daily tests running automatic connections to
T-Mobile and other major carriers in the USA and other countries.

Are you sure the "fast.t-mobile.com" APN should be used? Maybe your
new SIM cards require a different one like e.g. "wholesale"?

What is the output of "mmcli -m a"?

Also, try adding --timeout=300 to the --simple-connect call.


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