Microsoft® Lync Server 2010 Unleashed

Branch Site Survivability

Very similar to how voice resiliency can be achieved between multiple datacenters, branch office survivability depends heavily on using a separate registrar service. The size of the branch site plays a large factor in determining how the resiliency is achieved.

For branch sites of more than 5,000 users, it makes sense to deploy an entire Lync Server 2010 Front End pool in a highly available configuration to where user accounts are homed. Just as in a datacenter, failover scenario user accounts use the local pool as a primary registrar and a pool across the WAN link as a backup registrar. Figure 28.4 shows how the primary and backup registrars operate for a branch office user.

Figure 28.4 Branch Site Resilience

Medium-sized ...