>I setup a linux box to be a gateway for my friend's
>company. The system uses PPP to connect with netcom.
>It works O.K. at the beginning. But the PPP link
>is down around every 2 days. We don't know the reason
>of link down. It is not hard to put a checking script
>in cron. But I would like to know the reason. Any hint ?
There is no code in the pppd process, nor the drivers (either ppp or
the tty) which say "Oh, I have been running for two days . . . I guess
that it is time to disconnect."
The most common reason for this is that the modem has simply
disconnected. It may come from a wide variety of reasons. A very
common one is the failure to re-synchronize due to line noise. The
v.FC modems are very notorious for this problem.
You should check the logs. When pppd decides to terminate and
disconnect the modem, a message for the cause is written to the
log. The pppd process will have handlers for the common signals. You
should not send SIGTERM to the pppd process as that will cause it to
terminate. It will handle SIGHUP and SIGINT. Both will cause a message
to be written to the logs.
If you just find SIGHUP, then check the modem. My modem has a command
such as "ATI2" to display the status for the termination. You should
check to see if your modem has such a display.