Deploying Win2003 Internet Authentication Service (IAS) with VLans

Going through the "Deploying Windows Server 2003 Internet Authentication
Service (IAS) with Virtual Local Area Networks (VLANs)" Document,
http://www.microsoft.com/downloads/d...displaylang=en,
to setup an IAS server to communicate to my HP 2524 switches. I am trying to
set things up but the instructions ask for some information I cannot find.
It is asking for the "tunnel-tag" for my switches, but HP doesn't use that
terminology and I cannot find the info on the Internet. Anyone know where I
can get this information?

Thanks