Detect free roaming

[Aleksander Morgado]

On Fri, Mar 25, 2016 at 7:11 AM, Vincent Bernat <bernat at luffy.cx> wrote:
> My plan including free roaming in some countries. On my Android phone,
> when I am under this condition, the phone doesn't display the "R" for
> roaming. So, it seems to detect that I will not be charged. With modem
> manager, there is no such distinction, I always get the "roaming"
> mention.
>
> I don't know how the free roaming stuff is detected. Any chance it could
> be advertised correctly?

SIM cards have some files where operators can specify "networks which
they can be assumed to be the home network" (SPDI list IIRC). This is
the case e.g. for virtual operators which don't have their own
network, and may also be the same case for your sim card. In
ModemManager we specify "roaming" always if the device is not in its
home network; the modem itself reports that roaming flag in that case,
without considering the SPDI list. There's a very old branch which
added some support for parsing SPDI list and showing the correct
operator name (i.e. the SIM card operator instead of the service
provider network operator when needed), but that never got merged:
https://cgit.freedesktop.org/cgit/?url=ModemManager/ModemManager/log/&h=aleksander/display-rules

Not sure if you could give that a quick run, although not sure if it
even works with the modem you're using. The parsed SPDI list would be
shown in the "mmcli -i 0" output (showing SIM info).

-- 
Aleksander
https://aleksander.es