[Asterisk-Users] Modem as PSTN interface?

[PHP Mechanic]

> Hi, all
>
> Can a normal PCI modem be used to provide PSTN interface? I have seen 
> modems that have answering machine capabilities, so there should not be a 
> problem sending voice through them.
>
> Certainly, modem will be cheaper option then dedicated cards. Am I missing 
> something?

Most modems don't operate at full-duplex. A normal modem can be used to send 
voice, then switch to recording voice, but it can't send and receive 
simultaneously.