samba - Dec 2005 - Samba in Secondary Domain Controler ? Urgent Please Help me

Hi

for my big problems of winbindd crash, i want know if it's possible
to replicate a Domain Controler Active Directory ?

Actually, My Samba/Winbind use a Primary Domain Control based on the network
but not in the same LAN. The traffic use a VPN ... i thinks that the 
number of request
are big for the VPN tunnel.

Can i say to my Samba that duplication the Active directory in local for 
the winbind/squid
authentifie with local request ?

thanks bye