The Remote Agent Subgroups form is no longer used as part of the Networked ACD Programming. It still exists on the switch, but is no longer configured.
In a cluster, Remote Directory Numbers are assigned to each remote agent skill group. Clustered deployments allow configuration of ACD resiliency.
In non-clustered (legacy) environments, ACD resiliency is not supported. Each remote agent group must be assigned a remote agent sub-group ID (using the ACD Remote Agent Subgroups form). Non-clustered deployments are no longer recommended.