fibocom: Minimum PDP context ID

[Sven Schwermer]

Hi again,

On 3/8/22 21:25, Aleksander Morgado wrote:
>> Speaking of the default EPS bearer, should ModemManager be aware of that
>> bearer somehow, i.e. list it as an active bearer object etc?
>>
> 
> Yes, we could do that, definitely. There is no chance of getting the
> profile id wrong in Intel-based modems I think, if they support CID 0,
> that should be the one used for the initial EPS bearer.
> 

I have a follow-up question about the initial EPS bearer for the Fibocom 
MA510 modem. That modem appears to use CID=1, i.e. a regular PDP context 
for the initial EPS bearer. When configuring an incorrect APN for CID=1, 
the modem will not register successfully. Clearing the settings for 
CID=1 (`+CGDCONT=1`) or configuring the correct settings fixes this.

I guess the cleanest way to make ModemManager handle this correctly, 
would be to implement `create_initial_eps_bearer`. However, is the 
default profile manager aware of the initial EPS bearer and will not try 
to re-use its CID (in this case CID=1)?

Somewhat related: What are the differences between 
`load_initial_eps_bearer` and `load_initial_eps_bearer_settings`?

Is there a standard AT command to read out the SIM's default APN?

Best regards,
Sven