1.3 Overview

The Remote Desktop Protocol: Licensing Extension is designed to allow authorized remote desktop clients or users to connect to a terminal server (A reference to terminal server in this document generally implies a terminal server in app-server mode). It involves communication between a Remote Desktop client, a terminal server, and a license server. The terminal server can be configured to function in per-device or per-user license mode. Client access licenses (CALs) are installed on a license server, so that when a terminal server requests a license on a client's behalf, the license server issues a license out of its available pool of licenses.

The Licensing Extension also provides a mechanism for remote desktop clients to send their client access licenses (CALs) to personal terminal servers. The presence of these CALs in such connections is not designed to control access to the target machines but can be used to turn on or off specific RDP features reserved for licensed clients. The communication involved here is limited to communication between the Remote Desktop client and the personal terminal server. No license server is involved in any part of the communication.