While working as OCS administrator, we must know the communicator client and Address server communication.
Here are the useful information regarding Address Book Server.
The Address Book URLs (that is, one internal and one external) are the paths that clients use to access the data files in the Address Book Server file store. These URLs are configured under the Address Book tab in the Web Components Properties for the given Standard Edition server or Enterprise pool, and are retrieved through in-band provisioning (absInternalServerUrl and absExternalServerUrl) by the client when it logs on to its Standard Edition server or Enterprise pool. The clients can also have these URLs configured through Group Policy Objects.
Communicator client- > Address book Services
Active Directory -> User Replicator -> Database -> Address Book Services -> File Store (NTFS) – IIS 6.0 Server.
