[asterisk-users] Detecting answer with an analogue card

[Stephen Bosch]

Andrew Kohlsmith wrote:
> On Monday 05 February 2007 8:26 am, Stefano Corsi wrote:
>> 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?
> 
> Put it this way: Any serious Asterisk install that wants to pass the wife test 
> will have "progressinband" turned off in a fairly short order.

For those of us without first-hand experience here, what happens when
using "progressinband"?

My own experience is that call progress detection -- mostly with respect
to remote hangup detection -- is spotty, and I'm in North America.

>> 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?
> 
> I think you're starting to reach beyond what's practical.  But yes, something 
> like that would work just fine, because both ISDN BRI/PRI and SIP are digital 
> protocols and employ the concept of line state beyond the simple "on 
> hook/offhook".

...and at this point, why wouldn't you just put a BRI card in the
Asterisk server and skip the intermediate hardware?

-Stephen-