[Samba] Samba with multiple locations

[Tri Tu]

Hello,

I'm looking for a way to make global authentication with samba (both 
Unix & Windows).  The issue that I'm having with is adding machine into 
the domain from the remote locations.  I'm using slave ldap on all 
remote locations and set smbldap-tools point to slave local server & 
remote master ldap server.  Sometime it's working, sometime it's not.  
Most of the times, I just try to add the machine a second time and it 
joins to the domain OK from the remote locations.

Is there anyone know what is the best solution to use samba with 
multiple locations/branches?  Please give me your advices and I'm really 
appreciated.

Thanks.