Kindly guide me about vCAC Identity Appliance.
Kindly give me information about Identity Appliance and its function? If we already have our virtual environment up and running on 5.5 and SSO, do we still require the Identity Appliance?
You can use the vSphere SSO for vCAC or you can use the identity appliance itself. The identity appliance is SSO that was designed to work with vcac and as such gets updates and such on the same schedule as the other vCAC appliances so the choice is yours. My personal opinion and choice was to use the Identity appliance so that all the services were consistent across the board.
Oh one thing to add, if your vSphere SSO's are behind a loadbalancer you are going to need to use the Identity appliance. AFAIK vcac can only connect to a single SSO instance