I have CME 3.2, on a 2821 running ver 12.4. I have both 7940G and 7936 phones and need to somehow create the ability for a conference/call bridge where users (all using voip) can dial in, no more than 48 total. They all go through the same 2821 router. Someone told me that I would have to get at least Unity Express AIM ver 3.1 to accomplish this. Can anyone assist?