I need some clarification, this is my first centralised topology that we are configuring. The HQ has cucm be 7 and remote has cme. I want to have the remote site connect to the HQ and use cme in srst mode for fall back. I am a bit confused with something though, what protocol does the voice gateway at the HQ has to configured with, is it H323? I saw this in a cisco press book but with no explanantion why.. I would like someone to guide me as to what is the best way.