We have addressed the three types of Windows 2003 Terminal Server licenses – per user, per device and external connector. Now we need to mention (ah ha! The plot thickens!) that you will also need a standard Windows Server 2003 Client Access License (CAL). In order to legally access a terminal server, each client seat requires: Windows Server 2003 Client Access License and Windows Server 2003 Terminal Server Client Access License.
A Server CAL will provide basic access, including the ability to store files, print and be part of an active directory. The TS CAL grants remote access to users. It’s not as confusing as it seems, but you have to be mindful of terms and conditions for licensing.