First published on CloudBlogs on Mar, 12 2010
[April, 2010: Updated to clarify CAL types]
Many of our customers have multiple versions of Remote Desktop Session Host servers (formerly known as terminal servers), such as Windows 2000 Server, Windows Server 2003, and Windows Server 2008, and Windows Server 2008 R2, in their environment. A remote desktop connection to any of these host servers requires a client access license (CAL) of the same or higher version. The CALs are installed on and managed by a Remote Desktop license server by using Remote Desktop Licensing Manager (RD Licensing Manager).
This blog explains how to install and manage different version CALs on a single Remote Desktop license server.
What CALs can a specified license server manage?
Any license server can manage all lower version CALs along with the current version. For example, a license server that is running Windows Server 2008 R2 can manage all lower version CALs including Windows 2000 Server, Windows Server 2003, and Windows Server 2008. These CALs can be installed and managed by the Licensing Administrator on the license server by using RD Licensing Manager in Windows Server 2008 R2.
The license server running Windows Server 2008 R2 will also be able to cater to requests from all lower version terminal servers appropriately, allowing the customer business to continue seamlessly.
Beginning with Windows Server 2008 R2, terminal servers are now called Remote Desktop Session Host servers. All earlier versions are still referred to as terminal servers.
The compatibility matrix below shows which CALs can be managed by which license servers.
Windows 2000 Server
Windows Server 2003
Windows Server 2008
Windows Server 2008 R2
Windows 2000 Server CAL
Windows Server 2003 CAL
Windows Server 2008 CAL
When a lower version CAL is migrated or installed on a higher version license server, do the rights of the CAL change?
No. For example, if you install a Windows Server 2003 Terminal Services client access license (TS CAL) on a license server running Windows Server 2008 R2, that CAL will only allow the user to access a terminal server running Windows Server 2003 or lower; you cannot use it to access an RD Session Host server running Windows Server 2008 R2.
Can a license server manage higher version CALs?
No, a license server can only manage CALs of the same version or lower. For example, a license server running Windows Server 2003 can manage Windows Server 2003 TS CALs and Windows 2000 Server TS CALs, but not Windows Server 2008.
Note that Windows Server 2008 R2 CALs are compatible with Windows Server 2008 CALs, so both can be managed by Windows Server 2008 (as well as by Windows Server 2008 R2).
For more information, see
Windows Server 2008 RDS and Windows Server 2008 TS CAL Compatibility