Event ID 20 — Terminal Services Client Access License (TS CAL) Availability

Applies To: Windows Server 2008

When a client—either a user or a device—connects to a terminal server, the terminal server determines if a Terminal Services client access license (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.

TS CALs are installed onto a license server by using the TS Licensing Manager tool.

Note: A terminal server running Windows Server 2008 can only communicate with a license server running Windows Server 2008.

Event Details

Product: Windows Operating System
ID: 20
Source: Microsoft-Windows-TerminalServices-Licensing
Version: 6.0
Symbolic Name: TLS_W_LOWLICENSECOUNT
Message: The Terminal Services license server "%1" does not have a sufficient number of permanent Terminal Services client access licenses (TS CALs) for product "%3". Only %2 permanent TS CALs remain. To resolve this problem, purchase and install additional TS CALs as needed for this license server.

Resolve

Purchase and install TS CALs onto the license server

To resolve this issue, purchase and install the appropriate type of Terminal Services client access licenses (TS CALs) onto the Terminal Services license server. For more information about TS CALs, see "Terminal Services Client Access Licenses (TS CALs)" in the TS Licensing Manager Help in the Windows Server 2008 Technical Library (https://go.microsoft.com/fwlink/?LinkId=101639).

Important:  The Terminal Services licensing mode configured on a terminal server must match the type of TS CALs available on the license server.

Purchase TS CALs

To purchase TS CALs, do one of the following, depending on your country or region:

Install TS CALs on to the license server

Note: The automatic TS CAL installation method requires Internet connectivity from the computer running the TS Licensing Manager tool. Internet connectivity is not required from the license server itself. This method uses TCP/IP (TCP port 443) to connect directly to the Microsoft Clearinghouse. You can also install TS CALs onto the license server by using a Web browser or by the using the telephone. For more information about these installation methods, see "Install Terminal Services Client Access Licenses" in the TS Licensing Manager Help in the Windows Server 2008 Technical Library (https://go.microsoft.com/fwlink/?LinkId=101643).

To perform this procedure, you must have membership in the local Administrators group, or you must have been delegated the appropriate authority.

To install TS CALs automatically:

  1. On the license server, open TS Licensing Manager. To open TS Licensing Manager, click Start, point to Administrative Tools, point to Terminal Services, and then click TS Licensing Manager.
  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  3. Ensure that the connection method for the Terminal Services license server is set to Automatic connection (recommended) by right-clicking the license server on which you want to install TS CALs, and then clicking Properties. On the Connection Method tab, change the connection method if necessary, and then click OK.
  4. Right-click the license server on which you want to install the TS CALs, and then click Install Licenses. The Install Licenses Wizard starts.
  5. Click Next.
  6. On the License Program page, select the appropriate program through which you purchased your TS CALs, and then click Next.
  7. The License Program that you selected on the previous page in the wizard will determine what information you will need to provide on this page. In most cases, you will have to provide either a license code or an agreement number. Consult the documentation provided when you purchased your TS CALs.
  8. After you have entered the required information, click Next.
  9. On the Product Version and License Type page, select the appropriate product version, license type, and quantity of TS CALs for your environment based on your TS CAL purchase agreement, and then click Next.
  10. The Microsoft Clearinghouse is automatically contacted and processes your request. The TS CALs are then automatically installed onto the license server.
  11. To complete the process, click Finish. The license server can now issue TS CALs to clients that connect to a terminal server.

Verify

To verify that Terminal Services client access licenses (TS CALs) are installed and available on the Terminal Services license server, use the TS Licensing Manager tool.

To perform this procedure, you must have membership in the local Administrators group, or you must have been delegated the appropriate authority.

To verify that TS CALs are installed and available:

  1. On the license server, open TS Licensing Manager. To open TS Licensing Manager, click Start, point to Administrative Tools, point to Terminal Services, and then click TS Licensing Manager.
  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  3. In the left pane, expand All Servers, and then click the license server. In the right pane, the type, version, and number of TS CALs installed on the license server is listed.

Note:  To verify that the terminal server can discover (contact) a Terminal Services license server with the appropriate type of Terminal Services client access licenses (TS CALs), use Licensing Diagnosis in the Terminal Services Configuration tool on the terminal server.

Terminal Services Client Access License (TS CAL) Availability

Terminal Services