Crash in Modem-Manager on Ubuntu

[Aleksander Morgado]

On Mon, Aug 15, 2016 at 12:51 PM, Ajay Garg <ajaygargnsit at gmail.com> wrote:
> Thanks Aleksander for the reply.
>
> A small query, if a modem supports both DirectIP and QMI, which is the
> recommended mode?
>

If I'm not mistaken, Sierra Wireless is suggesting to use QMI or MBIM,
they are obsoleting Direct IP.

> AT-command-set is highly modem-specific, while QMI is a standard-protocol.
> So, if there are "n"  modems supporting both DirectIP and QMI, they are
> guaranteed to expose identical QMI "APIs", while their AT "APIs" could
> potentially be different.
>
> Are my thoughts in line?

Not really. Different QMI modems may also use different versions of
the protocol; e.g. some newer QMI devices don't support the generic
DMS commands we use to manage SIM-PIN, and we need to use some new UIM
service specific commands for that. So the picture is not so clear
with QMI either.

If you're happy with the ModemManager interfaces, though, none of this
should matter to your implementation. ModemManager should provide the
same functionalities in both Direct IP and QMI modes, at least for the
subset of features you're looking for (connection, SMS messaging,
signal quality retrieval).

-- 
Aleksander
https://aleksander.es