[Openal] Audio part reminders

[angelo]

Hi all,

i have a quite strange problem, i try to describe it as best as 
possible, anyway it seems related to OpenAL internal audio handling.

I have a half-duplex network audio streaming application, and i am using 
OpenAL to reproduce the incoming streaming and to capture and send the 
output streaming.
Audio format is a simple PCM 8Kkz 16bit monom, and after have 
implemented a "receiver/player" and a "capture/sender" the audio quality 
is good on both sides.
The problem is that, after talking to the microphone (capture+TX) and 
switching to RX(start receiver+player, a little part of the audio sent 
is played from the receiver, before the received audio get played. Same 
happen after receiving, starting transmission (capture), a little part 
of the received audio that was in the received OpenAL buffer is played 
in the remote side.

So it seems that part of the audio received finish in the transmit 
buffer (get someway mixed from openal). Transmitter and receiver are 
developed in 2 different thread, using different buffers, receiver user 
6 openAL buffers, capture use a different one.

For the receiving part, i tryed already to clean the buffers with

alSourcei (source, AL_BUFFER, 0);

or writing a null data buffer with alBufferData, without success.

Any help or suggestion is still appreciated.
angelo