What's in a name? That which we call the Edge...

I recently deployed CAC on Lync for a customer. There was a large number of sites, but they had kept AD up to date and the information was in a format we could use to define all the sites in Lync. So I exported it to a CSV, dusted off my Excel skills, and had half the info I needed to complete my task. I then worked with the Network Gods to determine how much bandwidth they could spare for Lync traffic. A quick design document and a slide deck or two to explain what we were doing and we were ready to go.
So our change request was approved, I had all the info I needed and soon the change window rolled around. I created the polices we needed, created the sites, imported the subnets it was a text book implementation. The only problem was that no one was around to test, but never mind how could anything have gone wrong?
The next morning I eagerly checked the Lync CAC report but it wasn't reporting anything, maybe no calls had been blocked yet I thought. I then opened up the Bandwidth Policy Monitoring Tool and there was nothing going on. I then made some test calls and still couldn't see anything. It was time to get into the Logging Tool to see what was going on.
It turns out that when the Edge Server was defined in the topology and installed the FQDN was not used. For some reason, Federation, PIC and Remote Access were all working without and issue but CAC was unhappy.
To resolve this, I just had to include the Primary DNS Suffix on the Computer Name settings of the Edge server and reconfigure the Edge server in the Lync Topology. I then needed to rerun the install on the Edge which actually uninstalled the Lync software (because the server name was no longer in the topology) and then reexport the topology and reinstall the Edge.
After all this CAC was working perfectly and the only problem that was experienced was some unhappy campers in sites that had insufficient bandwidth and consequently were unable to make calls.

So for Matt's 5 cents:
Always use the FQDN when defining your Edge Servers in the Topology. The Edge server (if you have one) plays a critical role in CAC working correctly thanks to ICE. If you're having trouble sleeping and would like to know more, you can read this article which explains how this is all hanging together http://msdn.microsoft.com/en-us/library/ff595756.aspx.