Is my SIM card defective or is my provider annoying me?

I am trying to establish a PPP connection using pppd and AT commands. This usually works fine with the SIM card of my local provider. However, I received a card from a friend who lives in Germany, and I wanted to try it in Switzerland, but I have very strange behavior.

Firstly, I cannot activate the error message (AT + CMEE), I always get the error message "ERROR", despite the fact that I previously activated the full text (AT + CMEE = 2). These commands work with my local vendor SIM ...

Then, if I check the status of the network:

AT+CGREG? +CGREG: 1,3 

Setting “3” means “Registration denied” .

When I try to connect or disconnect, I always have an error without explanation (despite AT + CMEE = 2):

 AT+CGATT=0 ERROR AT+CGATT=1 ERROR AT+CGATT? +CGATT: 0 OK 

I can send SMS using AT commands! Putting a SIM card into the phone, I can’t set any call!

So, is it possible to send SMS without having to register on the network? Is it possible for error messages to be disabled on the SIM card? I am wondering if this is a configuration problem, a problem with a SIM card or a provider problem ...

Edit

If this can help someone. I tried to send an SMS when I am disconnected from the network with my working SIM card, it works! I believe this website. I think my friend didn’t pay the bill, or my local network provider refuses to use my network ...

+4
source share
1 answer

It may be possible to roam data with circuit switching (GSM). And GPRS roaming is not allowed.

AT + CGREG? GPRS registration status returns.

AT + CREG? returns network registration status (GSM / UMTS). Try the command:

  AT+CREG? 

He will probably return 5 (Registered, roaming).

Sending SMS messages works because it does not need GPRS. Attach and + CGREG - all for GPRS.

+6
source

Source: https://habr.com/ru/post/1387220/


All Articles