In Office Communications Server 2007 R2, the RTC database stores user information. The RTC database on the Office Communications Server 2007 R2 back-end server maps Active Directory user globally unique identifiers (GUIDs) and security identifiers (SIDs) to users and SIP URIs. As a result, backups taken of the SQL Server database contain these mappings.

If Active Directory Domain Services (AD DS) encounters a problem and is not restored as part of the service restoration procedure, a database restoration of the RTC database can restore Office Communications Server 2007 R2.

If you need to restore the Active Directory domain, these mappings will change and you will need to export user data from the RTC database, rebuild your Active Directory domain, and then import user data back into the database. If you rebuild a domain, you cannot simply restore the database backup, because it now contains obsolete mappings to the previous domain.

For infrastructure settings, use the deployment plan of your organization to ensure that settings are as required.