Cisco Unified Communications IM&P Cluster
Figure 14-8 illustrates the Cisco Unified Communications IM&P cluster architecture maximum option of up to six servers per cluster.
Figure 14-8 Cisco Unified IM&P Cluster
A cluster can be formed to scale Cisco Unified Communications IM&P to support up to 45,000 licensed presence users. The Cisco Unified Communications IM&P server uses the same virtualization approach that is used by CUCM or Cisco Unity Connection.
Cisco Unified Communications IM&P consists of up to six servers, including one server that is designated as a publisher. Cisco Unified Communications IM&P utilizes the same architectural concepts as the CUCM publisher and subscriber. Within a Cisco Unified Communications IM&P cluster, individual servers can be grouped to form a subcluster, and the subcluster can have at most two servers that are associated with it.
The figure shows the topology for a Cisco Unified Communications IM&P cluster. The Cisco Unified Communications IM&P cluster can also have mixed subclusters, where one subcluster is configured with two servers while other subclusters contain a single server. The Cisco Unified Communications IM&P servers form their own cluster even if they are integrated as subscribers in the CUCM cluster.