What NAC System is This?

It looks like UNC is using the Enterasys NAC product.

As Paul noted in his article: "Because of university policy against endorsing vendors, UNC declined to name vendors for this story."

Still, looks like you might have an answer in the comment right above mine :-).

It is the Enterasys Sentinel product.

Enterasys Sentinel is now known as Enterasys NAC - see http://www.enterasys.com/products/advanced-security-apps/enterasys-network-access.aspx for more

Here's their next article.

We did some tech stuff, saved bazillions of dollars, our users think we're gods, shaved our IT dept. down to three guys living in a mobile home somewhere in Ohio. But policy prevents us from giving you any USEFUL information, so suck it - find out the hard way like we did.