[asterisk-users] Detecting answer with an analogue card

[Stefano Corsi]

At 13.44 05/02/2007, you wrote:
>On Monday 05 February 2007 5:18 am, George Camilleri wrote:
> > How does going digital help?
>
>Digital calls have a state associated with them.  They can tell if 
>the far end
>actually picked up (i.e. answered) or not.  Analog devices can't do this, or
>rather you can make them try (progressdetect) but it's difficult and as such,
>results are unpredictable.

Uhm... I still don't understand... Does call progress detection work 
fairly well for analog cards with the US telephony system, or it's 
still something experimental and randomly working? And if it's 
working in US, how difficult can it be to port it to the (for 
example) Italian system?

As an alternative, what about having a device (let's say Inalp Patton 
gateways) connecting to the telco with ISDN and to Asterisk with 
ethernet/SIP. Should I get correct ANSWER detection (and thus correct 
billing CDR records) with this setup?

Thanks and rgds
Stefano