Sampling Frequecy on BeagleBoard

     We are presently working on a VoIP application using
BeagleBoard.We are calling from BeagleBoard to a Desktop Phone(SJ
phone).But there is packet loss and clarity isues at the beagleBoard
audio output side ,if we speak something at the sj phone side.
We are having alsa driver and the sampling frequency we set is 8000hz.

     I would like to know is this sampling frequency supported by
Beagle Board.
If no wat is the recommended sampling frequency to be set.

Somebody pls help to solve this problem.

Smitha Rajan