So I was going to use CallManager 4.1(3) in my lab, but my friend at Berbee (CDW) said to use 6.0. He told me that the CCIE lab is going to jump right from 4.1 to 6.0 and that is what I should be learning. I only see CallManager 4.1 and 5 on the CCVP. He said that 6 is really 5.2, but Cisco didn't want to call it 5.2 and wanted to call it 6.0 instead and change the name to UC or something like that. Can anyone confirm this? What should I study? I am very confused.