Question : Server 2008 R2 RDP licensing and issues

I have a question regarding Microsoft Licensing and a problem regarding Windows Server 2008.
The scenario is... there are several time clocks that connect back to a server through an RDP connection. Also, there are several users that connect back to that Server through an RDP connection. The server is loaded with Server 2008 R2. There are 50 Server 2008 Remote Desktop device cals for all of the time clock and business software users. At most there are only 40 users that could possibly ever connect to the server. Almost immediately the time clocks stopped working correctly. Most all of the time clocks will disconnect at night and when they do come back up they are showing the previous day’s times. There is a message from the server saying the Remote Desktop manager is out of licenses. There are never any more than 30 connections at any given time. It’s almost like the server is remembering every Remote Desktop connection and has used the 50 licenses up and it’s just letting users on temporarily and then at night it’s disconnecting them.  

Answer : Server 2008 R2 RDP licensing and issues

Your problem is simple.
You need to determine what makes more sense in terms of RDS CAL licensing for your environment. If you have multiple shifts for example, where workers share the same computers (meaning more users than devices) it makes sense to license per device. If users connect from several locations (home, multiple office PCs, laptops, etc meaning more devices than users) you should have per user licenses.
As pointed out these are NOT concurrent.
The other thing to keep in mind is per DEVICE licensing is ENFORCED what means if you run out of licenses you do not connect. Simple as that (you actually get a temporary RDS CAL and after 90 days with no RDS CALs available that one expires and you get screwed).
As a workaround until you get more licenses you can simply delete the registry key HKLM\Software\Microsoft\MSLicensing on the device that cannot connect and it will get a new temporary RDS CAL good for 90 days.
For more information about licensing please download and read the guide I wrote, "Terminal Services A to Z" available at no cost at http://www.wtslabs.com. It explains all that and much more.

Cláudio Rodrigues
Microsoft MVP - Remote Desktop Services
Citrix CTP