Remote Desktop Services (formerly Terminal Services) provides a licensing grace period during which users are able to establish Remote Desktop sessions on an RD Session Host server without valid RDS CALs having been installed on an RD license server. This period should not be confused with the validity period of a temporary Remote Desktop Per Device CAL, which is 90 days, or the length of time that a permanent Remote Desktop Per Device CAL will remain assigned to a particular device, which is a random period from 52 to 89 days.
The length of the licensing grace period varies depending upon the operating system installed on the RD Session Host server, as shown in the following table:
|OS Running on the RD Session Host Server||Grace Period|
|Windows Server 2012||120 days|
|Windows Server 2008 R2||120 days|
|Windows Server 2008||120 days|
|Windows Server 2003 R2||120 days|
|Windows Server 2003||120 days|
|Windows 2000 Server||90 days|
The Session Host server logs a warning in its System log when the grace period is about to expire. At the end of the grace period, if there is not a license server present with valid RDS CALs installed, users will no longer be able to establish RDP sessions on the RD Session Host server, and errors will be logged in the server’s System log. The client will receive an error similar to one of the following:
To restore the full functionality of the Session Host server, it will be necessary to ensure that it is configured to connect to a valid RD license server and that the appropriate RDS CALs have been purchased and installed.