Sms answer to a ring call

[Andrea Viscovich]

I am wondering if it possible,
with gsm modem, to listen to phone call,
get the callerid, and replying with an sms to it.
This to save an sms. Say you are using kannel to
access a database by sending an sms, which kannel
is answering calling an url which gives back always the same result.
Is it possible (in the future) for the modem to do it?
Thanks in advance
Andrea