Sierra Wireless EM7455

Ralph Plawetzki ralph at
Thu Jun 9 07:27:11 UTC 2016

Am 08.06.2016 um 15:25 schrieb Bjørn Mork:
> Well, back to the real problem and possible soution: You can flip the
> modem into QMI mode by using a Sierra vendor specific QMI request, via
> the QMI-over-MBIM service.  I don't think this is implemented in any
> "proper" tools, but I have a perl script which can do it here:
> BIG FAT WARNING:  I would not have tried this if I were you.  The script
> is never tested on any modem with an OEM vendor PID originally, AFAIK.

Thanks for pointing me to this possibility. I will not try it.

In my experience with linux systems over the years "try and error" does
not lead to anything. The only way out of an issue is to identify the

Right this seems not possible here. I am neither a driver developer nor
a hardware specialist. I understand that the modem has 'Qualcomm
Snapdragon' in its name, so probably is running in QMI mode. I don't
know what QMI mode really means and where the difference is compared to
MBIM mode.

I also understand that MBIM is more usual and used on a broader base and
that newer devices need this magic code FCC authentication to get activated.

My modem needs that too and I can get it online, but as described it
gets a local IP then. From searching the web, many people had problems
getting the modem online or getting an IP at all.

So badly for me, there is something wrong with my hardware. As I do not
know which of the involved components (NetworkManager, ModemManager or
maybe the firmware) is responsible for retrieving an IP, from my point
of view it does not make sense to go any further from this point.

> This is a Lenovo modem in a Lenovo laptop, right?  If not then I got the
> rest wrong.  But in case that is correct:

Well, the laptop is bought from Lenovo, the modem inside identifies
itself as 'Sierra Wireless EM7455 Qualcomm Snapdragon X7 LTE-A'. I don't
know if that means that it is a Lenovo modem.

Again thanks a lot for the quick responses and trying to help! :)

Kind regards,

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