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.
