TMG Roll ups

Hi,

I am using TMG2010. A question is regarding Roll up installation. I have installed a Roll up 5 on TMG 2010 SP2 server.

My question is, is it mandatory to install all the Roll ups from (1 to 5) on TMG 2010 SP2 or only Roll up 5 is enough?

Please also suggest me the order of installation of Roll up?

Thanks