Question on Mobile Identification Number for GSM

[Dan Williams]

On Fri, 2014-10-31 at 14:09 +0100, Aleksander Morgado wrote:
> On Fri, Oct 31, 2014 at 8:57 AM, Aleksander Morgado
> <aleksander at aleksander.es> wrote:
> >> So for now, you can read the "Imsi" property of the Sim interface, and
> >> then the OperatorIdentifier property of the Sim interface.  Strip the 5
> >> or 6 digit OperatorIdentifier (which is the MCC/MNC of the issuing telco
> >> eg "310260") off the front of the Imsi, and you've got the MSIN.
> >
> > Problem being that you may not know exactly how many digits to strip
> > (5 or 6). I have a built-in database of MNC lengths developed for
> > ModemManager somewhere in a branch, but it wasn't perfect (lots of
> > issues in India IIRC). Still, that may be a
> > not-perfect-but-still-useful approach? I believe that Ofono ended up
> > doing the same. BTW; my need of this database of MNC lengths wasn't to
> > get the MSIN, but to actually get the MCCMNC of the SIM card and
> > expose it in the interface...
> 
> 
> This is the branch I was referring about:
> http://cgit.freedesktop.org/ModemManager/ModemManager?h=aleksander%2Fmnc-length
> 
> And this was the patch introducing the MNC length guess:
> http://cgit.freedesktop.org/ModemManager/ModemManager/commit/?h=aleksander/mnc-length&id=3feb7c8d148c8ea03cb46b535a4eccd9fb7966fa

This was for SIMs that don't set the MNC length, right?  I forget
whether we thought that was a rare occurrence or more common.

Dan