Multiple Forests, Central Forest
Office Communications Server 2007 R2 supports multiple forests that are configured in a central forest topology. Central forest topologies use contact or disabled user objects in the central forest to represent users in the other forests. The central forest also hosts user accounts for any users in this forest. A directory synchronization product, such as Microsoft Identity Integration Server (MIIS), manages the life cycle of user accounts within the organization: When a new user account is created in one of the forests or a user account is deleted from a forest, MIIS synchronizes the corresponding contact or disabled user account in the central forest.
A central forest has the following advantages:
Office Communications Servers are centralized within a single forest.
Users can search for and communicate with other users in any forest.
Users can view other users’ presence in any forest.
MIIS automates the addition and deletion of contact or disabled user objects in the central forest as user accounts are created and removed.
Before users can use Office Communications Server, the contact or disabled user objects in the central forest must be enabled for the Office Communications Server service.
The following figure illustrates a central forest topology. In this figure, there are two-way trust relationships between the domain that hosts Office Communications Server, which is in the central forest, and each user-only domain, which is in a separate forest. The schema in the