Hi,
Assuming you are making voice calls the bandwidth depends on the codec used. Here is what I found:
Codec BW reserved per call
===== ====================
G.711(a-law or u-law) 80K
G.723.1 & G.723.1A(5.3K) 22K
G.723.1 & G.723.1A(6.3K) 23K
G.726(16K) 32K
G.726(24K) 40K
G.726(32K) 48K
G.728 32K
G.729(all version) 24K
-Massimo
