RTC Upgrade to 4.0.3 and Splitting of CCM and JTS

: I would still perform the upgrade first.  This way testing can be done in a tested configuration before making any changes.

Unless I misunderstood what is being attempted or there is a proxy in the topology, since the URI is not changing and only the appServer is then I would have to guess that both jts and ccm will be running on the same host.  The concern I have with not changing the uri is that both appServers will be attempting to bind to the same host:port combination.  In this scenario the first appServer to start will be able to bind where the other will get a port conflict.

I would upgrade first. 

For splitting jts and ccm, I suspect the uri will need to change.  If this is the case, then a server rename will be needed...a PMR will need to be openned to work with support to 1)validate a server rename is appropriate and 2)provide the server rename key.

If a rename of the URI is needed depends on the URI the server already has.
Is a proxy configured?

If there is already a proxy working and the URI has no port within you won't need to rename the server.

If your URI contains a port you will need to do a rename I think as you have to get the port outside the URI. The proxy forwards your requests to the application defined with special ports (e.g. 9443 for ccm; 9445 for rrc, etc)

Hope this helps,
Simon