I ran into this issue today. I am so grateful for this forum. Before I start to somewhat answer javaman34's question and ask my own. I just want to put it out there that I hate Mitel's configuration/administration menus. They don't make it easy, you almost have to be an expert.
javaman34, you can attempt to configure it yourself or get a dealer to help you. Usually a dealer tech will configure this for you. Here is a link I found that may help you
http://mitelforums.com/forum/index.php?topic=12132.0 . Essentially you have to create links (extensions) between your MAS (Mitel Application Server, AWV) and your controller. This will allow the 3300 controller to access the additional resource (audio/video conferencing) on the MAS server.
My issue is I had a conference call that maxed out one extension (8 max I think), additional callers were not directed to the next (hunt) extension. It gave them the "busy" message when they called the first extension. Whey is this happening? Where can I check?
I only have 2 licensed sip channels on the 3300(the default). Does the configured AWV use these channels?