Probably one of the most confusing things ever created by mankind is Microsoft Licensing. In regards to Windows Server 2003, terminal services licensing has undergone some changes. Most notably is it no longer contains any built-in license like Windows 2000 Server did for 2000/XP clients.

Terminal Services licensing is comprised of three components, the Microsoft Clearinghouse, Windows 2003 Terminal Server Licensing Server and, of course, Windows 2003 Terminal Servers. The clearinghouse is used to activate license servers and to install/activate Client Access Licenses. The licensing server can be any version of Windows Server 2003 that has the Terminal Server Licensing Server installed, and it can be installed on the terminal server itself. The Terminal Services Licensing server stores all Terminal Services CAL tokens and then tracks the tokens once they have been issued. The licensing server must be available to the terminal servers and must be activated. If it has not been activated it will only hand out temporary licenses for 90 days. Once the temporary period has expired, you will need to purchase and install CAL's. If a terminal server cannot locate a license server after 120 days, it will not be able to allow any logons.

When purchasing CAL's there are a number of different types and you want to be sure you purchase the correct type. You will need to choose between Per User CAL's and Per Device CAL's. Per Device CAL's are issued to devices that are connecting to a terminal server, they are useful for shared computers. Per User CAL's are issued to users that are connecting to a terminal server.

Per User and Per Device CAL's are tracked separately on the license server and it is possible to have some TS in Per User mode and others in Per Device mode if you wish. A Terminal Server cannot run in both Per-User and Per-Device but you can have a mix of them in your organization. A Terminal Services Licensing server can serve CAL tokens to terminal servers in any combination of Per User/Device modes if the you have installed the proper licenses. There are 7 types of licenses a 2003 Terminal Server Licensing server can accommodate, we have already talked about temporary licenses, here is a look at the other six types.

Windows 2003 License Types

Windows Server 2003 Terminal Server Device CALs - —Windows Server 2003 terminal servers that are in Per Device licensing mode will request a Per Device CAL from the Terminal Services Licensing server.

Windows Server 2003 Terminal Server User CALs— - Windows Server 2003 terminal servers that are in Per User licensing mode will request a Per User CAL from the Terminal Services Licensing server.

Windows Server 2003Terminal Server External Connector licenses— - This type of CAL will allow unlimited connections to a terminal server running Windows Server 2003 by external users.

Windows 2000 License Types

Windows 2000 Server Terminal Services CALs - —Terminal servers running Windows 2000 Server will request these licenses from the licensing server for clients running OSes other than Windows 2000 Professional or Windows XP. You only need these licenses if you have terminal servers running Windows 2000 Server Terminal Services.

Windows 2000 Server Terminal Services Internet Connector licenses— - These licenses allow as many as 200 simultaneous anonymous connections to a terminal server running Windows 2000 by non-employees over the Internet.

Windows 2000 Built-In CALs - Clients that are running Windows 2000 Pro or Windows XP are issued a token from the built-in pool of license tokens when connecting to a terminal server running Windows 2000 Server Terminal Services.

As you can see, a Windows Server 2003 Terminal Server Licensing server can also issue licenses for Windows 2000 Terminal Servers. This allows you to minimize the number of license servers in your organization. In my opinion, if you have one terminal server its best to install the license server on the terminal server itself. If the TS goes down the lack of a licensing server won't be a concern. If you have multiple terminal servers, I put the licensing server on a DC, or another server that is always running.