Intercluster Peers Overview
Intercluster peering provides the ability for users in one cluster to communicate and subscribe to the presence of users in a different cluster within the same domain. For large deployments you can use intercluster peering to connect your remote IM and Presence clusters.
Intercluster peering is configured on the database publisher node of both the local and the remote cluster.
For sizing and performance recommendations for intercluster deployments, see the chapter "Collaboration Instant Messaging and Presence" in the Cisco Collaboration System Solution Reference Network Designs (SRND) at http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/uc_system/design/guides/UCgoList.html#48016