asterisk users - Oct 2007 - Multi-site / Multi-server coordination

Okay, so we are planning for the future here where I work so we are  
trying to do testing ahead of time as we might be setting up a  
satellite campus that would need its own Asterisk phone system but  
still tied into our main campus phone system.  This much we have  
accomplished.  We have a central database that routes calls to the  
correct server before "dialing" the final destination SIP phone (or  
Zap, IAX, whatever).

Our last big question is this: How, if at all, does asterisk deal  
with multi-server voicemail?  i.e. User A is at site A and has a  
voicemail in his mailbox.  He knows it really belongs to user B (who  
is at site B) so after listening to the voicemail he forwards it to  
user B.  Is there a way for Asterisk to realize this box belongs on a  
different machine and communicate the voicemail over the network to  
that machine, or is this something I need to write? :)

Daniel Hazelbaker
Information Technology Director
High Desert Church