[asterisk-users] Detecting answer with an analogue card

[Stefano Corsi]

> > I have two TDM2400 card with some 40 FXS modules and 4 FXO modules. I
> > would like use analogue lines for outboud calls.
> > How is it possibile to detect ANSWER?
>you cannot. it's analogue, no signalling is done on it.
>
>unless you write dsp routines to detect the right things
>at the right moment :)
>
>if you want exact cdr records, you must go digital.

There's still something I don't understand: when using a simple modem 
on an analog line, you get correct answers from the modem: "NO 
ANSWER", "BUSY", "NO DIALTONE", etc... why is this possible with 
these TDM2400 cards that cost twenty times as much?

I know that I'm probably missing something... could you help me 
understand what?

Thanks
Stefano