Re: PPP Modem Hangup

On Tue, Sep 10, 2024 at 11:30:48AM -0700, Devesh Chipade wrote:
> In my options file, I have debug and kdebug 7.
> This is all the logs I could get:

The pppd logs look fine.  There is nothing in the kernel (dmesg) log
that looks relevant (in fact kdebug 7 is mostly useful if you are
actually debugging the kernel driver; it doesn't really help with
problems like this).

Do you have logs from pppd on the ubuntu/linux side?  Is something
causing it to terminate?

Alternatively, do you have another service running on either side
which also thinks it is using the same serial port?  Something like a
getty, or whatever the systemd equivalent is for providing a login
prompt?  You could do "fuser /dev/ttyMSM0" or "fuser /dev/ttyUSB0" as
root during the 6 seconds when the link is up to check if something
other than pppd also has the serial port open.

Paul.