Keep the following in mind when preparing for and carrying out disaster recovery procedures.

• Plan for disaster recovery when you do your capacity planning. For disaster recovery capacity, each pool in a paired pool should be able to handle the workloads of the Call Park services in both pools. For details about Call Park capacity planning, see Capacity Planning for Call Park.

• During disaster recovery, users who have been redirected to the backup pool as part of the failover process use the Call Park service running in the backup pool. Therefore, support for Call Park during disaster recovery requires the Call Park application to be deployed and enabled in both the primary pool and the backup pool.

• Each pool must have a valid range of orbit numbers for users who are homed in that pool to use for parking calls.

• Always keep a separate backup copy of any customized music on hold that has been uploaded for Call Park. These files are not backed up as part of the Lync Server 2013 disaster recovery process and will be lost if the files uploaded to the pool are damaged, corrupted, or erased.

You can define only one set of Call Park application configuration settings and one customized music-on-hold audio file per pool. These settings include the timeout threshold, music on hold, maximum call pickup attempts, and timeout URI. To view these configuration settings, run the Get-CsCpsConfiguration cmdlet. For details about the Get-CsCpsConfiguration cmdlet, see Get-CsCpsConfiguration.

During disaster recovery, Call Park uses the Call Park application in the backup pool, so settings in the primary pool are not backed up. If the primary pool can't be recovered and you deploy a new pool to replace the primary pool, the settings from the primary pool are lost, and you need to reconfigure the Call Park settings and any customized music-on-hold audio files in the new pool.

If you deploy a new pool with a different fully qualified domain name (FQDN) to replace the primary pool, you need to reassign all the Call Park orbit ranges that were associated with the primary pool to the FQDN of the new pool. To reassign orbit ranges to the new pool, you can use either Lync Server Control Panel or the Set-CsCallParkOrbit cmdlet. For details about the Set-CsCallParkOrbit cmdlet, see Set-CsCallParkOrbit.