Terminal Server license server roles
Updated: January 19, 2009
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Terminal Server license server roles
A Terminal Server license server stores all client licenses. A terminal server must be able to connect to an activated license server before clients can be issued permanent client access licenses (CALs). When you activate a license server, Microsoft provides the server with a digital certificate that validates server ownership and identity. By using this certificate, a license server can make transactions with Microsoft and receive client licenses for your terminal servers. If you install a license server but do not activate it, that server only issues temporary licenses.
For small deployments, it is acceptable to install both the terminal server and Terminal Server Licensing on the same physical computer; however, for larger deployments, consider installing Terminal Server Licensing on a separate server. Note that one Terminal Server license server can serve many terminal servers concurrently.
You must configure Terminal Server Licensing correctly in order for your terminal server to continue to accept connections from clients. To allow ample time for you to deploy a license server, Terminal Server provides a licensing grace period, during which no license server is required. During this grace period, a terminal server can accept connections from unlicensed clients without contacting a license server. The grace period begins the first time the terminal server accepts a client connection. It ends after you deploy a license server and that license server issues its first permanent CAL, or after 120 days, whichever comes first. For more information about the licensing grace period, see Terminal Server Licensing grace period.
Before installing a license server, determine which of the two license server roles you require—a Domain license server or an Enterprise license server. During Terminal Server Licensing setup, you select one of these roles. By default, the Enterprise license server role is selected.
If you are installing a license server in an Active Directory domain environment, you can select either the Enterprise license server or the Domain license server role. If you are installing a license server in a workgroup or a non-Active Directory domain environment, you must select the Domain license server role. To activate the license server quickly, install Terminal Server Licensing on a server that has Internet access.
Enterprise license server
You can only install an Enterprise license server on a domain controller or a member server in a domain, not on a stand-alone server. This role is published to Active Directory.
An Enterprise license server is an appropriate choice if your network includes several domains, and if you want to maintain one license server that can issue licenses to terminal servers across the different domains. An Enterprise license server can serve terminal servers in any domain, but the domain must be a Windows Server 2003 domain or Windows 2000 Active Directory domain. An Enterprise license server is automatically discovered by any terminal server that is in the same site as the license server. By default, an Enterprise license server only serves terminal servers in the same site.
Domain license server
A Domain license server is an appropriate choice if you want to maintain a separate license server for each domain. Terminal servers can access domain license servers only if they are in the same domain as the license server.
License server discovery process
Terminal servers use a discovery process to locate license servers. This process begins when the Terminal Server service starts. Although Terminal Server attempts to detect a license server automatically, you can explicitly specify a preferred license server to which the terminal server connects. For instructions on configuring a preferred license server through Group Policy or by modifying the registry, see Set preferred Terminal Server license servers. You can also set preferred license servers by using a Windows Management Instrumentation (WMI) script. For three scripts that you can use to set preferred license servers, delete preferred license servers, or query preferred license servers, see "Preferred License Server WMI Scripts" in Windows Server 2003 Terminal Server Licensing (http://go.microsoft.com/fwlink/?LinkID=26220).
During the discovery process, terminal servers attempt to contact license servers in the following order:
Any preferred license servers that are specified in Group Policy.
Any Enterprise license servers or Domain license servers that are specified in the registry.
In Windows Server 2003, the relevant registry key is LicenseServers , and it is located under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TermService\Parameters.
In Windows 2000, the relevant registry key is DefaultLicenseServer, and it is located under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TermService\Parameters.
In Windows Server 2003, you can specify multiple license servers in the registry. In Windows 2000, you can only specify one license server.
Enterprise license servers that are specified in Active Directory.
Domain license servers.
Enterprise license server discovery
As mentioned in this topic, an Enterprise license server is automatically discovered by any terminal server that is in the same site as the license server and by default, only serves terminal servers in the same site. You can, however, publish the license server to another site in Active Directory. A terminal server polls Active Directory every 60 minutes to locate an Enterprise license server, and continues to poll every 60 minutes, even when an Enterprise license server is located.
Domain license server discovery
If you are installing a Domain license server, the computer on which you install the license server must be a domain controller for it to be automatically discovered by terminal servers that communicate with it. If you install a Domain license server on a member server, you must specify this server as a preferred license server on all terminal servers that need to communicate with it. If the computer on which you plan to install the Domain license server is in a workgroup, it can only be automatically discovered by terminal servers on the same subnet.
If you install an Enterprise license server on a member server, you do not need to specify it as a preferred license server, because Enterprise license servers are automatically discovered.
When a terminal server attempts to locate a Domain license server, the terminal server queries all domain controllers within the same site. If the terminal server cannot find an available license server in the same site, the terminal server will not attempt to query any other domain controllers (for example, other domain controllers in the same domain). A terminal server attempts to locate a Domain license server every 15 minutes. After a Domain license server is located, the terminal server continues to search for a Domain license server every two hours. If the terminal server cannot locate a Domain license server, it resumes searching every 15 minutes.
To improve security, you should consider removing workgroups and replacing them with domains.
For more information about Terminal Server and Terminal Server Licensing, see Guidelines for Deploying Terminal Server (http://go.microsoft.com/fwlink/?LinkID=34627) and Windows Server 2003 Terminal Server Licensing (http://go.microsoft.com/fwlink/?LinkID=26220).