I'm running Debian Woody, and I have a internal modem of undetermined origin.

Everything works fine unless I forget I'm connected and wander away for 20 min. or so. When I come back I find I am disconnected cleanly from my ISP( i check plog and it says the session EXITed) , but the phone line has no dial tone, like the modem hasn't 'given the line back'.

No amount of unplugging the line from the modem, or anyhting short of rebooting fixes it. Is there a way to reset the serial port, or connect to the modem directly and tell it to 'let go'?

Needless to say it's killing my uptime. I have to do this about once a week.

JP