The replication of Microsoft Exchange Server directory information between Exchange servers within an Exchange organization. The Exchange directory database contains information about the various recipients in the organization and configuration information for all components of Exchange.
Directory replication is a process that copies this information between Exchange servers so that all Exchange servers in an Exchange organization have easy access to this critical information.
Directory replication in an Exchange organization gives each Exchange server a complete, up-to-date copy of all directory information for the entire organization. Directory replication occurs differently depending on whether Exchange servers are in the same site.
Within an Exchange site, intrasite replication of directory information takes place automatically and uses remote procedure calls (RPCs) between servers. You cannot configure this operation. Replication takes place approximately five minutes after a change is made to the directory. The server in which the change was made notifies other directories one at a time, and the other servers send the first server RPC messages requesting updates to the directory.
Between Exchange sites, intersite replication requires that you first establish messaging connectivity between sites using a connector such as the Site Connector. Then you must install and configure the Directory Replication Connector. Replication of directory changes takes place using standard e-mail messages communicated between the Exchange directory services on each machine.
One server in each site is designated as a bridgehead server for requesting directory updates from the other site. You can schedule intersite directory replication to occur at off hours in busy networks or more frequently in networks in which frequent changes to recipients are made.