full duplex voice call

[irfan]

Hello every one...
i am writing an application for voice calls between two modems, (full
duplex speaker phone modems conexant RS56 sp PCI ) .
Now the problem is that i open wave in of my modem and then if i try to
open waveout of modem it gives me an error... i was thinking that
whether my modem is not full duplex. But i came to know that it is full
duplex but the drivers installed for this modem are Unimodem Half
duplex audio drivers ,,, is this the reason that i m not being able to
open both wave in adn waveout devices of my modem or there might be
some other reason. i am using TAPI 1.4 for my application....
One more thing to ask that can i make a full duplex call using such
technique i.e by opening wave in and wave out devices of my full duplex
modems.....
what else could be the possibilities
Thanks in advance , waiting for ur kink help
irfan