MC7455 'Call Failed'

Tim Harvey tharvey at
Thu Jun 22 15:10:03 UTC 2017

On Wed, Jun 21, 2017 at 10:00 AM, Aleksander Morgado
<aleksander at> wrote:
> On Wed, Jun 21, 2017 at 6:22 PM, Tim Harvey <tharvey at> wrote:
>> error: couldn't start network: QMI protocol error (14): 'CallFailed'
>> call end reason (1018): gsm-wcdma-option-unsubscribed
>> verbose call end reason (6,33): [3gpp] option-unsubscribed
> I believe the option-unsubscribed error is telling you your account
> isn't allowed to connect to that APN. I'd suggest to make sure the SIM
> and APN details are the correct ones.


Ah yes you are correct - I grabbed an un-activated SIM! Thank you, I
will add this to my troubleshooting notes.

The MC7455 presents two QMI+WWAN pairs which I think is quite common
for the Sierra Wireless modems. The first appears to be raw-ip and the
2nd 802.3. Most of the qmicli commands won't work on cdc-wdm0 (raw-ip)
and I believe this is expected but I'm not clear exactly why (could
you explain this?).

I can connect using libqmi directly on cdc-wdm1 (802.3) using 'echo
"APN=h2g2" > /etc/qmi-network.conf; qmi-network /dev/cdc-wdm1 start'
then use 'qmicli -d /dev/cdc-wdm1 --wds-get-current-settings' to get
the IPv4 configuration and set it manually (as dhcp won't work over
the raw-ip mode which qmi-network configures /dev/cdc-wdm1 as).

So now that I understand how to use these QMI modems directly using
libqmi I'm wanting to make sure I understand how to use modem-manager
and network-manager to connect. I'm finding that 'mmcli --modem 0
--simple-connect="apn=h2g2"'' doesn't appear to work:
root at ventana:~# mmcli --modem 0 --simple-connect="apn=h2g2"
successfully connected the modem
root at ventana:~# qmicli -d /dev/cdc-wdm1 --wds-get-current-settings
error: couldn't get current settings: QMI protocol error (15): 'OutOfCall'

Also, I'm unclear how to NetworkManager on the QMI devices:
root at ventana:~# nmcli connection add type gsm ifname cdc-wdm1 con-name
mc7455 apn h2g2
Connection 'mc7455' (5dc4516e-e857-4917-9542-0dee211b692a) successfully added.
root at ventana:~# nmcli connection up id mc7455
Error: Connection activation failed: No suitable device found for this

What is the appropriate interface to use for QMI devices (wwan1 gives
the same error)? This is supposed to be the 'control interface' not
the 'network interface' correct?


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