MC7455 - Connection sequence to LTE network

To answer your question,

here is the output of dmesg command regarding ttyUSB serial ports enumeration

[    5.304644] usb 2-2: Qualcomm USB modem converter now attached to ttyUSB2
[    5.305834] usb 2-2: Qualcomm USB modem converter now attached to ttyUSB3
[    5.307015] usb 2-2: Qualcomm USB modem converter now attached to ttyUSB4

/dev/ttyUSB3 port is enumerated (so i don’t know why at command are not supported by ttyUSB3 instead)

About the mbpl driver, I built it from source on my kernel so i don’t use GOBI
I mooved the kernel files generated :

  • qcserial.ko
  • qmi_wwan.ko
  • usb_wwan.ko

to /lib/modules/4.16.18+/kernel/drivers/net/usb/ and ran the following commands :

depmod 4.16.18+
update-initramfs -c -k 4.16.18+
reboot

I tried to follow the next steps on your thread here Example on establishing data connection by AT!SCACT via MBPL R20 driver

qmicli --device=/dev/cdc-wdm0 --wds-noop --client-no-release-cid

But i have no cdc interface so the command fails

Yet, dmesg tells me a cdc-wdm interface has been registered :

[    5.323756] usbcore: registered new interface driver cdc_wdm