A large firm (approximately 100,000 employees) may have multiple locations. By using master domains, the number of users per master domain can be as high as 40,000 because the machine accounts are kept in the resource domains. The company can create three master domains of approximately 33, 000 users each or, to accommodate growth of the user base, four master domains of approximately 25,000 users each.
Figure 2.6 Large Organization domain model
The domain in which a user is defined can be based on any grouping or sequencing, such as alphabetical, divisional, departmental, or by location. Which domain is used in defining a particular user is unimportant because a trust relationship exists between each resource domain and each master domain.