Microsoft Lync 2010 Attendant takes advantage of the high availability features in Microsoft Lync Server 2010 for enhanced client registration, discovery, and routing to improve service resiliency and flexibility in design and deployment of your Enterprise Voice solution. A well-designed Enterprise Voice deployment can help meet your requirements for “always on dial tone.”
The Lync Server 2010 Registrar is a service that tracks clients, authenticates users, and provides routing services. The Registrar is not a standalone server role but is installed on Standard Edition servers, Front End Servers, and Survivable Branch Appliances.
Each user is assigned to a particular Registrar pool, which becomes that user’s primary Registrar pool. Each pool has a designated backup registrar pool which is used in failure scenarios.
In the case of data center failure, assuming a resilient WAN link between the two data centers, users whose primary Registrar pool is no longer available are automatically connected to the backup Registrar pool. A client does not need to know its primary or backup Registrar pool. The first logon server—typically a Director—will always direct the client to either the primary pool or, in the event of failover, to the backup pool.
If clients fail over to their backup Registrar pool, the following voice features will be available: