Sunil, I can not advise you in that regard as i am not familier with AXE statistics.
Misa, The method that i explained you applies for any type of SS7 load (not only for ISUP) and even applicable for IN. I understand that this is not a very easy job as you need to know the details to it’s last byte, but in absense to any vendor specif tool, this is the only way to calculate the exact Traffic load. You will have to find out following items in order to be able to calculate
1- The IN BHCA
2- Number of messages between the HLR and MSC and IN because of IN, per BHCA
3- Messages length (number of bytes)of each message.
and then you can apply the method as explained earlier.