Overview of TS Licensing

Applies To: Windows Server 2008

What is TS Licensing?

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

When a client—either a user or a device—connects to a terminal server, the terminal server determines if a TS CAL is needed. The terminal server then requests a TS CAL from a Terminal Services license server on behalf of the client attempting to connect to the terminal server. If an appropriate TS CAL is available from a license server, the TS CAL is issued to the client, and the client will be able to connect to the terminal 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 TS CAL issued by a license server before they can log on to a terminal server.

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

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

• A permanent TS CAL is issued by a license server to a client connecting to the terminal 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 terminal server. The grace periods are as follows:

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

Before the TS Licensing grace period ends, you must purchase and install the appropriate number of TS CALs for each device or user that needs to connect to a terminal server. In addition, you must verify that the Terminal Services licensing mode that you specify on the terminal server matches the type of TS CAL available on the license server. The Terminal Services licensing mode determines the type of TS CAL that a terminal server will request from a license server on behalf of a client connecting to the terminal server.

Additional references

• Terminal Services Client Access Licenses (TS CALs)

• Checklist: Configure TS Licensing

• Install Terminal Services Client Access Licenses