Preparing the Head Office LAN
to Support CallManager Clusters
One essential ingredient in CallManager clusters is the assurance of bandwidth
between the servers themselves. Keeping in mind that the CallManager SQL
server databases are the main data to be synchronized, larger head office installations
might have some very large databases.The SQL servers can partially synchronize
only changed data, but nonetheless this is critical data.
Therefore, many large VoIP installations employ the use of virtual LANs
(VLANs) to the CallManagers so they can operate on their own dedicated bandwidth.
One separate VLAN is used to carry data traffic, and yet one more VLAN is
used to carry the voice IP phone traffic.This arrangement is shown in Figure 11.8.