Hi Nisha,
what should be the role of other system here
and how system is know where is the reference info base is ??
You must very clear, the system roles are defined well before by the global settings with the needed RFC all defined on that time itself. have you done?
Moreover reference base is not meant for any system, its the reference base from SAP standard tables, For example I want to compare my system with the other new releases from SAP itself.
more details. If you can compare your EHP4 with other latest version systems if you have in your landscape, (normally sandbox in client landscapes, option as reference system)
or
you can use any reference base from SAP Standard tables,
You can all the information very clearly with the help link available in the panel itself. That would be the best way to go with CDMC.
Please check.
Thanks
Jansi