i have a Sierra Wireless MC7455 is that compatible?
however i tried your recommendation but it doesnt work.
ifdown A1net- changed proto in /etc/config/network to 3g
ifup A1net
And then back to qmi same procedure
Also tried it in the LuCi interface.
And set proper interface. Not /dev/cdc-wdm0 but /dev/ttyUSB0/1/2/3 or whatever it allow you to connect.
So i set the device to /dev/ttyUSB2 in EDGE/GPRS/EV-DO and got connection with my private APN.
But when switching back to QMI Protocol and choose /dev/cdc-wdm1 i dont get a connection.
Why /dev/cdc-wdm1? Show
ifdown wan
uqmi -d /dev/cdc-wdm0 --get-signal-info
uqmi -d /dev/cdc-wdm1 --get-signal-info
Does this (also) work on 19.07.2 ? As I have problem, not to get IP when trying to use QMI with MC7455:
Hi!
Just taking a chance here. I see you guys are at least able to use UQMI at all.
I attached a Huawei e8372 dongle and am able to see in the logs that OpenWRT detected and a new interface was created.
However, UQMI is not working. I tried:
uqmi -d /dev/cdc-wdm0 --get-signal-info
uqmi -d /dev/cdc-wdm1 --get-signal-info
Saying “failed to open device.” 
Regards,
Vince
Ehh, Huawei e8372 is NOT qmi device. See https://www.rdeeson.com/weblog/179/gsm-internet-on-raspberry-pi-using-huawei-e8372-wifi-dongle , looks like normal hilink device. Set proto=dhcp and proper ifname.
Thank you sooooo much @cezary! I have been battling with this for several weeks thinking I am doing something wrong this certainly boosts my confidence again 
As a follow-on (hopefully last) question does this mean I cannot use scripting to send text messages and stuff?
Sincerely,
Vince
Hilink has its own API for this. If this device is compatible with this API, you should able write some script.
Hy,
heres a screenshot of the result from the commands.
Im getting signal on both but however connection to internet im only getting with cdc-wdm1 and only with dynamic APN on QMI.
With Modemmanager i can't choose either wdm1 or wdm0. It only says "Sierra Wireless MC7455" and also with Modemmanager both APN are working Private and Dynamic..
With QMI i can only get a internet connection on wdm1 with Dynamic APN but not with Private APN.
Yesterday i upgraded my Firmware of the MC7455 to latest version.
Still the same problem...
I discovered something.
When adding the WAN interface to LuCi i cant issue any command through uqmi CLI.
But whats much more suspicious, is that when i delete the interface from LuCi and then try to connect with uqmi CLI and after that issue the command '--get-data-status' it says 'connected'.
Is there really nobody who can help me with this.
Im getting really frustated now.
EDIT:
My fault found out that i need to do
Ifdown #interface
to issue uqmi commands
Im still fighting my MC7455.
Could you please provide the relevant part of /etc/config/network (wwan ?) for your MC7455,
and which uqmi-cmds you use, to get it up and running ?
Me too, I found that QMI cannot send any APN. Unable to connect to the private network. Please let me know if there is any solution.
Finally got it work..!!
Try to edit your /etc/config/network
Add this at the end.. But also be sure that you dont have any left overs from previous interfaces related to the MC7455.
config interface 'wwan0'
option ifname 'wwan0'
option device '/dev/cdc-wdm0'
option proto 'qmi'
option apn 'your.apn'
config interface 'wwan1'
option ifname 'wwan1'
option device '/dev/cdc-wdm1'
option proto 'qmi'
option apn 'your.apn'
change the APN to yours.
dont add any other info, like username or password
save and then issue the command
/etc/init.d/network restart
to restart the network interfaces.
And then also add both interfaces to the WAN zone of your Firewall
this way i think qmi can choose whatever "device" it wants to take to connect to the internet.
but i also cant explain WHY this is working
Credits to @pj0e
1 Like
I must add an account password. Only then can I access my private network.
Is this password specific for yourself and only for yourself or is it a password like mine > whoever uses this APN has to use "this" password.
If its like mine you can leave it out.
I need to fill in, APN access point, exclusive password, exclusive account.
Did you done it?
Does it works?