Kindly advise which is more suitable, I have a CAM and CAS running at 4.1.3 software on production, I want to upgrade it to NAC 4.5.1, which do you prefer? Performing a clean installation of NAC 4.5 using the .iso image, or ugrading the appliance to 4.5 using .tar?? Also, please advise the time that will be used for the upgrade, including testing and configuration. Thanks!!!