You manage the cluster directory number through SDS using Remote Directory Number (RDN) Synchronization.
To use Remote Directory Number synchronization to maintain the telephone directories of the elements within the network or cluster:
Review the description for RDN Synchronization.
Migrate the network or cluster to support RDN Synchronization (see Mitel Knowledge Base article 09-3070-00008, "Migrating to RDN Synchronization via SDS" on Mitel Online)
Proceed to Review the Remote Directory forms