[asterisk-users] Detecting answer with an analogue card

[Stefano Corsi]

"Eric \"ManxPower\" Wieling" wrote:

>>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?
>
>Because the far end sends a carrier tone.

Uhm... but wait: I remember old days modem to have also a VOICE 
return code... again, why should a 20$ box be able to detect VOICE 
while a 2000$ card shouldn't?

Rgds
Stefano