RS232 GSM Modem

[toabctl <toabctl googlemail com>]

Hi,

i want to use network-manager 0.8 in debian embedded system. I want to connect the system with network/modem manager to the gsm network and have a Siemens TC63i modem for that available.
I can manually use the modem with the AT-Commands, but i don't know how to setup the connection with network/modem manager.
Question:
1) How does network-manager detect that the modem is connected? Or how can i tell networkmanager on which port the modem is attached? I use a rs232<->usb adapter so the port is /dev/ttyUSB0 .
2) How does the connection-config looks like?

Cheers,

Tom