The three domain models, single domain, single master domain, and multiple master domain, make use of trust relationships. The trust relationships provides flexibility. For detailed information about the three domain models, see "Managing Windows NT Server Domains" in the Microsoft Windows NT Server 4.0 Concepts and Planning Guide.
The domain model you select should match the way you want to manage your organization. The number of users in the organization, the topology, and the location will also influence how domains will be designed, implemented, and where the resources will be located. Because there are few limits imposed by Windows NT software, other aspects of the computing environment must be considered to provide guidelines for the decisions you make about your domain model.
The following assumptions are made:
Unless otherwise noted, it is assumed that the Windows NT Server to be used as the PDC is a 486/33 machine (or higher) with 32 MB of physical RAM and a 1 GB hard disk. Test conditions at Microsoft included base Windows NT Server services, moderate file and print activity, Remote Access Service, SNA Server, and SQL Server.
Decisions made earlier in the process must be verified in light of information available later in the process. Therefore, you should anticipate making several passes through the process until all decisions at all steps match the available information.
There are many ways to implement your domain model. The following examples illustrate some of the flexibility of domains. These examples are followed by a list of business and equipment considerations that can affect your domain design.