Overview of Terminal Services

Terminal Services running on a Windows 2000 Server enables all client application execution, data processing, and data storage to occur on the server. It provides remote access to a server desktop through terminal emulation software. The terminal emulation software can run on a number of client hardware devices, such as a personal computer, Windows CE–based Handheld PC (H/PC), or terminal. The term Windows-based Terminal (WBT) broadly describes a class of thin client terminal devices that can gain access to servers running a multi-user Windows operating system, such as Terminal Services.

With Terminal Services, the terminal emulation software sends keystrokes and mouse movements to the server. The Terminal server does all the data manipulation locally and passes back the display. This approach allows remote control of servers and centralized application management, minimizing network bandwidth requirements between the server and client.

Users can gain access to Terminal Services over any Transmission Control Protocol/Internet Protocol (TCP/IP) connection including Remote Access, Ethernet, the Internet wireless, wide area network (WAN), or virtual private network (VPN). The user experience is only limited by the characteristics of the weakest link in the connection, and the security of the link is governed by the TCP/IP deployment in the data center.

Terminal Services provides remote administration of network resources, a uniform experience to users in branch offices in remote locations, or a graphical interface to line of business applications on text-based computers. Some of the benefits of Terminal Services include:

  • Allows the use of 32-bit Windows-based applications from devices that might not be Windows-based such as:

    • Windows for Workgroups 3.11 or later

    • Windows-based terminals (Windows CE devices)

    • MS-DOS-based clients

    • UNIX terminals

    • Macintosh

  • Clients that are not Windows-based require the use of a third-party add-on.

  • Requires minimal disk space, memory, and configuration for Terminal Services clients.

  • Simplifies support for remote computers and branch office environments.

  • Provides centralized security and management.

  • Is unobtrusive to applications and the existing network infrastructure.

Terminal Services is a built-in feature of Windows 2000. You can enable Terminal Services in one of two modes:

Remote Administration

Remote Administration gives system administrators a powerful method for remotely administering each Windows 2000 server over any TCP/IP connection. You can administer file and print sharing, edit the registry from another computer on the network, or perform any task as if you were sitting at the console. You can use Remote Administration mode to manage servers not normally compatible with the Application Server mode of Terminal Services, such as servers running the Cluster service. For more information about Windows Clustering, see "Ensuring the Availability of Applications and Services" in this book.

Remote Administration mode only installs the remote access components of Terminal Services. It does not install application sharing components. This means you can use Remote Administration with very little overhead on mission critical servers. Terminal Services allows a maximum of two concurrent Remote Administration connections. No additional licensing is required for those connections, and you do not need a license server.

Application Server

In Application Server mode, you can deploy and manage applications from a central location, saving administrators development and deployment time as well as the time and effort required for maintenance and upgrade. After an application is deployed in Terminal Services, many clients can connect—through a Remote Access connection, local area network (LAN), or wide area network (WAN), and from many different types of clients.

You can install applications directly at the Terminal server, or you can use remote installation. For example, you can use Group Policy and Active Directory to publish Windows Installer application packages to a Terminal server or a group of Terminal servers. Applications can only be installed by an Administrator on a per server basis, and only if the appropriate Group Policy setting is enabled.

Terminal Services cannot pass the Internet Protocol (IP) address of individual client computers to an application. Because this information is required by Windows Clustering, you cannot use Cluster service in Application Server mode.

Client licensing is required when deploying a Terminal server as an application server. Each client computer, regardless of the protocol used to connect to Terminal server, must have the Terminal Services Client Access License as well as the Windows 2000 Client Access License.