you need to know what IP codec is in use. If you are using G.711, you can get 64 calls (8 calls per DSP X 8 DSPs), if you are using G.729 for example, that takes 2 DSP resources per call, so you will only get 4 calls per DSP (4 x 8, or 32 calls max).
you can 'display ip-network-r 1" (or whatever you are using), this will have the codec set listed, then do a 'display ip-codec 1' (for example) to check which codecs could be used.
mitch
AVAYA Certified Specialist