Using qmicli with a Sierra Wireless EM7455

Aleksander Morgado aleksander at
Tue Jun 23 16:42:52 UTC 2020


> > > > I would advice to always use the "-p" option when running qmicli
> > > > commands, and also configure PROXY=yes in the qmi-network profile
> > > > you're using. But for your initial assessment it may not be strictly
> > > > necessary.
> > >
> > > Why should I do so?
> >
> > If you run your QMI commands through the qmi-proxy (or your MBIM
> > commands through the mbim-proxy), you can have multiple processes
> > running commands at the same time, as long as they all use the proxy.
> What means "running commands here"? Does it have influence on the data traffic?

It means running control commands, nothing to do with the data traffic.

> > > Attaching to packet service with 'mbimcli -d /dev/cdc-wdm0 --attach-packet-service --no-open=4 --no-close '...
> > > Saving state at /tmp/mbim-network-state-cdc-wdm0... (TRID: 5)
> > > Starting network with 'mbimcli -d /dev/cdc-wdm0 --connect=apn='internet.telekom',auth='PAP',username='telekom',password='telekom' --no-open=5 --no-close '...
> > > Network started successfully
> > > Saving state at /tmp/mbim-network-state-cdc-wdm0... (TRID: 7)
> >
> > This is good, the network connection to the APN you specified is now
> > up. The only thing missing is setting up the network interface with
> > the required IP settings.
> >
> > I truly don't remember whether your modem supports DHCP to setup the
> > network interface, because by default we don't do that in
> > ModemManager, given that not all MBIM modems have a DHCP server
> > running inside. Instead, what we do in MM, and what you should
> > probably do is use mbimcli --query-ip-configuration to retrieve what
> > are the IP settings to configure in the network interface.
> > mbim-network doesn't do that for you so far.
> I could run neither `mbimcli -d /dev/cdc-wdm0 --query-signal-state`
> nor `mbimcli -d /dev/cdc-wdm0 --query-ip-configuration` successfully.
> Whenever I issued any of these commands, it caused my connection
> apparently to be terminated.

Oh, yeah, this could be due to the implicit MBIM close run by mbimcli
after each command, unless you tell mbimcli not to do so. If you look
at the mbim-network sources you'll see the --no-close and
--no-open=TRID balancing to avoid this.

I believe you won't have these issues as soon as you run with the
mbim-proxy, because the proxy takes care of that, if I'm not mistaken.
Could  you retry your testing using the proxy? i.e. add PROXY=yes in
the mbim-network profile, and then issue all your manual mbimcli
commands with the additional "-p" option.

You could also run ModemManager to avoid needing all these low level
setup and tricks... :) I know a lot of people use mbim-network and
qmi-network, but these are too simple, they don't scale well.


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