User Authentication with CentralUserManagement??

Dear SOA Experts,

When I research documents, I have seen that authentication(user management) in CentaSite happens via external directory like LDAP. I am trying to understand whether it is possible to integrate with CentralUserManagement??If yes how we can achieve it?As per my understanding if we create user in centrally(by giving proper role assignment) in MWS,That user should able to login to CentraSite??Is my understanding correct? Can we achieve it?

Sorry I put many ???But my intension is to know about this possibility…

Thanks and Regards,