Device CAL’s ain’t no Device CAL’s ?

I stumbled upon a *real* weird problem. Apparently the terminal server licenses called “per Device” ain’t a real per device. From reading on it Microsoft states it like this:

Device-based versus User-based Terminal Server CALs

Two types of Terminal Server Client Access Licenses are available: TS Device CAL or TS User CAL.

  1. A TS Device CAL permits one device (used by any user) to conduct Windows Sessions on any of your servers.
  2. A TS User CAL permits one user (using any device) to conduct Windows Sessions on any of your servers.

You may choose to use a combination of TS Device CALs and TS User CALs simultaneously with the server software.

If I take the above and take a closer look at my terminal server license server I’ll see something like this:

Terminal services license manager
Terminal services license manager

As you can see, I *do* have devices with more than a single license (in fact, several of them do have more then four), which from my understanding ain’t what Microsoft had in mind.

After noticing this, I initially thought my terminal servers had the wrong license mode, but as you can see below, they are using “per Device“.

Terminal service license settings
Terminal service license settings

Which means, I am completely clueless at this point, as they *really* should be using just a single license, and not multiple ones.


Ok, after experimenting a bit with it, it seems that a license seems to be tied to the SSID. Which would explain, why I see different CAL’s for a single device. We reflashed the thin clients in between (and within that process, the SSID is freshly generated), so that’d be the only explanation I’ve got for what I’m seeing.