Question LTE Modem Not Connecting To Network

Aug 13, 2019
Hi all,

I am trying to use a ec21-j LTE modem inside a PCEngines apu2 board to connect to an LTE network using a simcard.

I have ubuntu 18.04 installed in the PCengines board no problem.
I installed the sim card and the LTE modem. These can be seen and queried. I can use the

qmicli --device /dev/cdc-wdm0 --nas-network-scan

to find networks (including seeing which are preferred). I assume that this means that i can access the state of the sim card just fine.

mmcli -m 0 also works just fine, listing the right sort of information.

My problem comes when trying to connet to the network:

$ sudo qmi-network /dev/cdc-wdm0 start

Loading profile at /etc/qmi-network.conf...
APN: ****
APN user: ***
APN password: *
qmi-proxy: no
Checking data format with 'qmicli -d /dev/cdc-wdm0 --wda-get-data-format '...
Device link layer protocol retrieved: raw-ip
Getting expected data format with 'qmicli -d /dev/cdc-wdm0 --get-expected-data-format'...
Expected link layer protocol retrieved: raw-ip
Device and kernel link layer protocol match: raw-ip
Starting network with 'qmicli -d /dev/cdc-wdm0 --wds-start-network=apn='',username='*',password='****' --client-no-release-cid '...
error: couldn't start network: QMI protocol error (14): 'CallFailed'
call end reason (3): generic-no-service
verbose call end reason (3,2001): [cm] no-service
Saving state at /tmp/qmi-network-state-cdc-wdm0... (CID: 20)
error: network start failed, no packet data handle
Clearing state at /tmp/qmi-network-state-cdc-wdm0...

Any ideas of either
  • where to ask
  • what is wrong
  • how to debug