Establishing data channel using PPP is not recommended.
You can change to use MBIM in AT!USBCOMP.
For example, below are some steps to use MBIM in Ubuntu 18:
- sudo apt-get install libmbim-utils
- Modify /etc/mbim-network.conf to include APN/username/password of SIM card
- sudo mbim-network /dev/cdc-wdm0 start
- sudo dhclient wwan0
- “ifconfig wwan0” should show IP address
- ping 8.8.8.8 -I wwan0
Below is the log for your reference:
owner@CNHKG-EX-001367:~/legato/workspace/git/mangOH_2-7-2019$ cat /etc/mbim-network.conf
APN=hkcsl
APN_USER=
APN_PASS=
APN_AUTH=
PROXY=yes
owner@CNHKG-EX-001367:~/legato/workspace/git/mangOH_2-7-2019$sudo mbim-network /dev/cdc-wdm0 start
Loading profile...
APN: hkcsl
Querying subscriber ready status 'mbimcli -d /dev/cdc-wdm0 --query-subscriber-ready-status --no-close'...
[/dev/cdc-wdm0] Subscriber ready status retrieved: Ready state: 'initialized' Subscriber ID: '454003074155184' SIM ICCID: '8985200012741551847' Ready info: 'unknown' Telephone numbers: (0) 'unknown' [/dev/cdc-wdm0] Session not closed: TRID: '3'
Saving state... (TRID: 3)
Querying registration state 'mbimcli -d /dev/cdc-wdm0 --query-registration-state --no-open=3 --no-close'...
[/dev/cdc-wdm0] Registration status: Network error: 'unknown' Register state: 'home' Register mode: 'automatic' Available data classes: 'lte' Current cellular class: 'gsm' Provider ID: '45400' Provider name: '1O1O' Roaming text: 'unknown' Registration flags: 'unknown' [/dev/cdc-wdm0] Session not closed: TRID: '4'
Saving state... (TRID: 4)
Attaching to packet service with 'mbimcli -d /dev/cdc-wdm0 --attach-packet-service --no-open=4 --no-close'...
Saving state... (TRID: 5)
Starting network with 'mbimcli -d /dev/cdc-wdm0 --connect=hkcsl --no-open=5 --no-close'...
Network started successfully
Saving state... (TRID: 6)
You can also see here for other method to establish data channel: