I did the switch over that you are describing, I am/was certified on Rel.23 Administration, on Meridian working on a 61C, an option 11C, and a bunch of option 11 compacts, all networked together.
Changed over to a 3rd Party Call center shop, using a G3R with Rel 9.5, moved it up to Communication Manager 3.0 on S8700 servers, and networked together 7 -S8700 sites, plus a remote site in Manila using 4620 IP Phones.
The difference from Meridian X11 to Communication manager is like, going from PC DOS to MAC OS.
Remember to make generous use of the help key <F5> using ASA. The biggest challenge you will face, is the difference in terminology. For some unknown reason, the software designers, and documentation writers at Avaya have allowed the Marketing types to get involved in labeling of stuff in the programming, so the terminology changes based on the version of the software. Example: the software name has changed from Definity up to release 10.5, then it changed to MultiVantage from release 11.1.X to 11.3.X, then it changed to Communication Manager from 11.3.2 to current release. They also appear to have dropped the first digit on the release numbers, so instead of Communication Manager 12.1, it is Communication Manager 2.1 .
Once you get used to some of these idiosyncrasies, it is easy. Best advice is use the Help key, second best is get a copy of the Administration manual for the version of software you are running from the Avaya support site. It has screen references for most commands, and fields that show on the admin screens, Acrobat will let you search the PDF for the thing you are looking for clarification on. When that is no help, call your Avaya support folks, if you have already done, the above, and you indicate that you are still having trouble, I don't know a tech that will give you a hard time, about asking a question when you have already read the manual.
Good Luck!
Cam
Links:
Commands:
list con soft <will tell you version of software you are running>