[Samba] Samba, LDAP and replica

[TI]

Hi Guys,

I have six Linux Servers running Samba 3 as PDC of our domain, in different locations. They are integrated through LDAP (which is configured to replicate over our VPN) and all responds to the same domain. So, wherever the user is, he will log in the same domain name. 

Now I'am planning to migrate to Samba 4. As Samba 4 manages it´s LDAP internally, what is the best approach to keep the same design I have today? 

Should I search for a way to keep Samba LDAPs replicated or there is better way, like configure remote Sambas instances to work as BDC ?

Thank you,

Edison