Before you install any of the Communications Services products, you need to understand which schema you will use. The schema is the set of definitions describing what types of information can be stored as entries in the directory. Two schema choices, Sun JavaTM System LDAP Schema 1 and Sun JavaTM System LDAP Schema 2, are available and supported with Communications Services. Your choice of schema depends on the following criteria:
Are installing Communications Services components for the first time
Are integrating Communications Services with other Java Enterprise System products, such as Portal Server
Have an existing version of any of the Communications Services components, for example, if you are upgrading from Messaging Server 5.2
See Chapter 8, Understanding Schema and Provisioning Options for more information on schema choices.