Host Security Integration uses the concept of "security domain" to manage user accounts. A security domain is a set of systems for which a given user account is valid. A security domain may consist of several servers, such as a Windows NT domain, or it may consist of a single SNA host computer. In another, less common configuration, several SNA host computers could form a single security domain if they implement a shared user database.
A host security domain is a collection of systems that share the same user database. The SNA Server administrator defines the boundaries of the host security domain by specifying the SNA Server connections to host computers. The host security domain name should relate to the collection of host computers and can be anything you choose; no host resource name needs to be matched.
When defining a host security domain, two synchronization options apply separately to user IDs and passwords. "Replicated" uses the same user ID or password in all security domains (Windows NT and host computers). "Mapped" allows you to have a different user name and password in each security domain, with the Host Account Cache maintaining the association. For example, a common configuration is the mapping of user IDs and replication of passwords. This allows you to have the same password but different user names on various host computers. During creation of the host security domain, SNA Server Manager creates a Windows NT group with the same name as the host security domain for subsequent use in enabling users.