CMC is the 5.0 follow on to VCS 4.x Command Central Availability. There is a new 3 day course on Wide Area Clusters being developed in Reading, UK (the pilot is the week of 30 July and I will attend). It appears from the docs that CMC requires the Symantec Product Authentication Service (previously called VxSS). This involves a root broker and each cluster member being an authentication broker. This is used for secure communications.
CMC allows wide area control of clusters, failing over entire sites to other sites in the event of a disaster or to avoid an emminent disaster, such as a flood or hurricane. CMC allows graphical reporting with predefined reports for up time/down time, etc. It has a Sybase database and the database is available in read-only mode to users to generate their own reports. It allows changing multiple cluster attributes across the spectrum, so you could set RestartLimit to 1 for all Listener resources for Oracle for example.
Setting this up is beyond the scope of this forum.