Remote Desktop Licensing (RD Licensing), formerly Terminal Services Licensing (TS Licensing), manages the Remote Desktop Services client access licenses (RDS CALs) that are required for each device or user to connect to a Remote Desktop Session Host (RD Session Host) server. You use RD Licensing to install, issue, and track the availability of RDS CALs on a Remote Desktop license server.

	Note
	In Windows Server 2008 R2, a terminal server is now called an RD Session Host server. Also, Terminal Services client access licenses (TS CALs) are now called Remote Desktop Services client access licenses (RDS CALs). In these Help topics, these new terms are used, even when referring to previous versions of Windows Server. Note that security group names have not changed in Windows Server 2008 R2.

When a client—either a user or a device—connects to an RD Session Host server, the RD Session Host server determines if an RDS CAL is needed. The RD Session Host server then requests an RDS CAL from a Remote Desktop license server on behalf of the client attempting to connect to the RD Session Host server. If an appropriate RDS CAL is available from a license server, the RDS CAL is issued to the client, and the client is able to connect to the RD Session Host server.

Although there is a licensing grace period during which no license server is required, after the grace period ends, clients must have a valid RDS CAL issued by a license server before they can log on to an RD Session Host server.

	Important
	Remote Desktop supports two concurrent connections to remotely administer a computer. You do not need a license server for these connections.

To use Remote Desktop Services, you must also have at least one license server deployed in your environment. For small deployments, you can install both the RD Session Host role service and the RD Licensing role service on the same computer. For larger deployments, it is recommended that the RD Licensing role service be installed on a separate computer from the RD Session Host role service.

You must configure RD Licensing correctly in order for your RD Session Host server to accept connections from clients. To allow ample time for you to deploy a license server, Remote Desktop Services provides a licensing grace period for the RD Session Host server during which no license server is required. During this grace period, an RD Session Host server can accept connections from unlicensed clients without contacting a license server. The grace period begins the first time the RD Session Host server accepts a client connection. The grace period ends after whichever of the following occurs first:

• A permanent RDS CAL is issued by a license server to a client connecting to the RD Session Host server.
  
  
• The number of days in the grace period is exceeded.
  
  

The length of the grace period is based on the operating system running on the RD Session Host server. The grace periods are as follows:

Operating system running on the RD Session Host server	Grace period
Windows Server 2008 R2	120 days
Windows Server 2008	120 days
Windows Server 2003 R2	120 days
Windows Server 2003	120 days
Windows 2000	90 days

By default, after you log on as a local administrator on an RD Session Host server, a message appears in the lower-right corner of the desktop that notes the number of days until the licensing grace period for the RD Session Host server expires.

Before the RD Licensing grace period ends, you must purchase and install the appropriate number of RDS CALs for each device or user that needs to connect to an RD Session Host server. In addition, you must verify that the Remote Desktop licensing mode that you specify on the RD Session Host server matches the type of RDS CAL available on the license server. The Remote Desktop licensing mode determines the type of RDS CAL that an RD Session Host server requests from a license server on behalf of a client connecting to the RD Session Host server.