So, lately I’ve been playing around with CUCM (yes, that’s the new name) 5.x. First, the OS installation is very sleek and works like a champ in VMWare. Something which was never very easy with Windows 2000 as the underlying OS. Finally, upgrading is very easy to do and it seems to work great too. Here is a screen shot of an upgrade from 5.1.1 to 6.0.1. So far so good.