Re: Automated selection of connections

[Colin Helliwell <colin helliwell ln-systems com>]

> On 10 July 2017 at 21:21 Alex Ferm <aferm petropower com> wrote:
>
> Hello all,
>
> I manage a bunch of cellular connected embedded devices running
> NetworkManager+ModemManager. I use the same software image on all
> devices regardless of which cell network they run on.
>
> My current solution to selecting the appropriate connection pivots
> around the sim-operator-id (I'm running NM 1.0.6, so I had to write a
> dbus client to manage that).
>
> My issue now is that we are switching to a private APN for one of our
> carriers. This will introduce a new connection configuration, however
> this time the sim-operator-id will be identical to one of our other options.
>
> Is there a sane way to determine the correct APN to use without setting
> up connection configurations for every modem that goes out the door? I'd
> like to continue to be able to provide updates for devices deployed with
> the old APN without too much work as well.
>
> I'd like to upgrade NM + MM on these devices, but that is not feasible
> in the near future.

Sorry to be replying with not an answer, but it's similar to an issue I'd like to address. We don't know 
whose SIM the user will plug in but would similarly like the system to figure out the APN to use and push it 
into the NM connection.
Though ModemManager can tell us the MNC/MCC that the device is registered with, we have (in the uk) service 
providers who use the network (I.e. mnc/mcc) of the larger operators' networks yet have their own APNs. And 
even on the big providers, payg sims etc seem to have different apns, but the modem sees nothing 
differentiating.
The Id on the sim itself ought to help, but I have at least one which doesn't have anything set.
Tricky one to figure out....