your modem woes.
Were once my modem woes.
1)  you have to know the AT HAYES command set.
2) you have to change the settings of the modem with kermit
3) you have to get the modem to behave correctly upon hangup
once you do that, and getty is listening to your modem,
it will work.
It's kind of involved, so I can't go into great detail now.
You should read the unix system Administration Handbook.
The section on terminals / serial connections is pretty
good.
Basically,
You have to get the modem to reset every time it loses a carrier
You have to get the modem into auto answer mode.
josh