VOIP Application

Hi all

I'm trying and develop a simple VOIP application on the BB to interact
with a Windows SW of ours based on jvoiplib. I saw many posts with
many problems in creating a VOIP application, but I hope this is due
to the attempt to port to BB a complex VOIP application; on the
contrary I need a raw code that can code/encode a bidirectional audio

Did someone ported jvoiplib on BB?
Otherwise is there an already BB ported lib that can receive an audio
stream encoded by jvoiplib?
I'm not sure the audio stream produced by jvoiplib is an actual
standard that can be decoded by another library. In any case we use
GSM compression type - GSM IS an european standard - and sixteen bit
sample encoding type as relevant compression parameters...
Supposing no positive answers to first two questions... what audio
coding/decoding lib do you suggest to work with?
Thanks in advance for any support!