Installation of DSfW (Forest Root Domain) in an enterprise introduces a logical DSfW forest with a single domain by extending the existing eDirectory tree or creating a new eDirectory tree. This forest can be further logically extended by introducing multiple sub-domains to support the needs of an organization. Understanding the needs of the organization in relation to the domain deployment scenarios described in this chapter is critical to a successful implementation. Organizations might require Active Directory-style authentication and authorization for all users in the eDirectory Tree. This need might arise either to support an Active Directory-based enterprise application or Member Server, or to provide Active Directory- style client workstation login and enterprise management.