Issues with SIMCOM A7872S Module and NetworkManager (nmcli)

[RobustSamar]

Hello everyone,

I am currently experiencing issues with a SIMCOM A7872S LTE module when NetworkManager is enabled on my system. The module interfaces via usb0.

Problem Description:

• When NetworkManager (nmcli) is enabled, the LTE module works for about 15 minutes, during which it can ping successfully.
• After this period, the interface (usb0) gets disconnected, and the connection is lost.

Attempts to Resolve:

I have tried to prevent NetworkManager from managing the usb0 interface by using the following methods, but the problem persists:

1. Editing the NetworkManager Configuration File:

   I created a configuration file named /etc/NetworkManager/conf.d/99-unmanage-usb0.conf with the following content:

   [keyfile] unmanaged-devices=interface-name:usb0

   Then, I restarted NetworkManager with:

   sudo systemctl restart NetworkManager

2. Using Udev Rules:

   I created a udev rule file /etc/udev/rules.d/99-unmanage-usb0.rules with the following content:

   ACTION=="add", SUBSYSTEM=="net", KERNEL=="usb0", ENV{NM_UNMANAGED}="1"

   Then, I reloaded the udev rules:

   sudo udevadm control --reload-rules sudo udevadm trigger

Questions:

1. Has anyone successfully used the SIMCOM A7872S LTE module with NetworkManager (nmcli)? If so, could you share your configuration?
2. Are there any specific configurations or settings that need to be applied for the SIMCOM A7872S module to work reliably with NetworkManager?
3. Is there a more effective way to prevent NetworkManager from managing the usb0 interface?

[JosephAtNXP]

Hi,

Thank you for your interest in NXP Semiconductor products,

We have not had a demo like the mentioned, we had a demo for a processor + RF but from QorIQ.

I'd suggest to confirm the power state of the device at all times and try with other modules.

Regards