Intra-Cluster Communication
As the name suggests, intra-cluster communication is the communication between
servers in the same cluster.Two types of information are communicated between
servers in the same cluster—CallManager database information, and real-time data.
The CallManager database contains the configuration of all IP telephony
devices.When this configuration is updated in the CallManager Administrator,
the information is stored in the local database of the CallManager Publisher.The
Database Publisher then sends this information to all the database subscribers in
the cluster, who then update their local copies of the database.
As you can see in Figure 4.1, CallManager database replication works as a
client/server model.This feature allows for consistency between databases, and
redundancy in the event of a server failure.