I have a two chassis setup, and i'm using it to route calls to other systems, voicemail, fax, etc.

I only have 30-40 active calls at any one time, but I need to be able to do routing for more than 400 DID #'s

Any ideas

(for example, 9600-9799 goes to a 4 channel VSF hunt group, DTMFing extension (via mailbox config in DID screen)

I guess you need a 1000 cabinet and processor. There are 1500 DID routing options and 24 DID groups.