AFAIK there is no hard number on the amount of call handlers you can have, only the HDD size would be a factor since all require an entry in the DB.
And yes, usually when you mention AA and you use Unity or CUC that's the same as call handlers.
HTH
java
If this helps, please rate
www.cisco.com/go/pdihelpdesk
HTH
java
if this helps, please rate