VOIP/ATM

Hi there, I am doing a study on VIOP, and I have to find an answer to a pretty urgent problem.

we code the voice according to the standard G729 (1 screen of 10 bytes every 10 ms) and encapsulate it on IP, i.e. we encapsulate the screens on RTP (which adds 12 bytes), on UDP (which adds 8 bytes) and on IP (20 octets)… we use several technologies :

1. we encapsulate IP on AAL 3/4 in ATM on Vc-12, and we ecapsulate 4 screens per datagram.
2. one encapsulates IP on AAL 5 in ATM on Vc-3, and one ecapsule 2 screens per datagram. Cells ATM having a fixed size.

we would like to know the maximum number of conversations that can be transmited in each case. thanks a lot for any help.