Sierra Wireless EM7345 4G LTE (MBIM) not working

Bjørn Mork bjorn at
Mon Jun 16 23:31:32 PDT 2014

Harald Jung <jung at> writes:

> Hi,
> Problem: Sierra Wireless EM7345 4G LTE (MBIM) not working

I've got one of those as well, and it works fine.  But only with MBIM.

> here are the infos that I've collected:
> Kernel: 3.14.3
> Module cdc-ncm
> Networkmanager:
> Modemmanager: 1.2.0
> Jun  3 14:39:16 Ecos-Appliance kernel: cdc_ncm 3-10:1.0: MAC-Address:
> ff:ff:ff:ff:ff:ff

This is the first problem with NCM:  The MAC-Address announced by the
firmware is not valid.  Easily fixed of course, but still an indication
that they don't really care about NCM.

>       CDC NCM:
>         bcdNcmVersion        1.00
>         bmNetworkCapabilities 0x00
>       CDC Ethernet:
>         iMacAddress                      6 FFFFFFFFFFFF
>         bmEthernetStatistics    0x00000000
>         wMaxSegmentSize               1514
>         wNumberMCFilters            0x0000
>         bNumberPowerFilters              0

As you can see in these descriptors: It looks like a "placeholder" where
Sierra has failed to fill in valid content.

The last hint is the fact that Lenovo (where I assume you got this
modem?) only provides an MBIM driver for the older Windows versions
without builtin MBIM support.

So: Use MBIM with this modem.  It's currently the only supported mode.


More information about the ModemManager-devel mailing list