RDP Support in Windows CE (Windows CE 5.0)
Remote Desktop Protocol (RDP) is the native presentation protocol for Microsoft® Windows NT® Server 4.0 and later, Terminal Server Edition and Microsoft® Windows® 2000 Terminal Services and later. RDP allows a thin client, such as a Windows-based Terminal, to communicate with a Terminal Server across a local area network (LAN) or a wide area network (WAN) or by means of a dial-up, Integrated Services Digital Network (ISDN), digital subscriber line (DSL), or virtual private network (VPN) connection. The RDP protocol uses TCP/IP as its transport protocol and is based on the recommended standard for data protocols for multimedia conferencing (ITU T.120), as defined by the International Telecommunications Union.
In Windows CE, RDP has two modes of operation. By default, RDP runs in Graphics, Windowing, and Events Subsystem (GWES) rather than in its own process space. RDP runs in GWES as a Windows control, and the interface to it is through standard window messages. This means if RDP is configured to run in GWES, it cannot be run inside a Web browser. Optionally, you can configure RDP to run in Microsoft® ActiveX® Control instead of a standard windows control.
RDP 5.2 provides the following functionality:
- Unicode compatibility, which enables you to send Unicode values of characters as virtual key codes to the keyboard input.
- Supports operation in any environment that allows network localization, automatic disconnect, and remote configuration.
- Variable bandwidth allocation through client-side bitmap caching and optional compression for low-bandwidth connections, significantly improving performance over low-bandwidth connections.
- Multichannel-capable protocol that permits separate virtual channels for carrying presentation data, serial-device communication, licensing information, and heavily encrypted data.
- Remote control lets the support staff view and control a Terminal Services session. Sharing input and display graphics between two Terminal Services sessions lets a support person diagnose and resolve problems remotely.
- Network Load Balancing (NLB), available in Windows 2000 Advanced Server and Datacenter Server.
- High color 8-bit, 16-bit, and 24-bit graphics are supported if they are also supported in the graphics driver.
- Clipboard sharing, also known as clipboard redirection. The local clipboard becomes a part of the clipboard viewer chain in the remote session, allowing the user to copy and paste between applications running in both the remote session and on the local client.
- Local-printer redirection so server applications can print locally to the client device.
- Local audio playback so server applications can direct audio to the client device or play at the Terminal Server.
- Local-port redirection so server applications can use parallel and COM ports of the client device.
- Local drive redirection so server applications can use the file system (including ATA) of the client device.
- File redirection filter that permits exposing only specific directories. If you specify that only external storage, such as Compact Flash or USB storage, be exposed through the redirected drive, information is saved only to the redirected drive.
- TS CAL maintenance tool. This control panel utility is available in any OS design that supports Control Panel programs, such as the Enterprise Web Pad. It requires that RDP client be in the run-time image.
- Can be run in GWES rather than in its own process space. This reduces the overhead of a call to a function in another process.
Windows NT Terminal Server uses RDP 4.0 as its native data protocol. Windows 2000 Terminal Services uses RDP 5.0, while Windows XP Professional Edition uses RDP 5.1. Microsoft Windows CE 5.0 uses RDP 5.2. All versions are compatible, so Microsoft Windows CE clients can connect to any of these servers.
Note The Windows Installer does not permit installations from a Remote Desktop Connection.
For more information on the ITU-T T.120 data protocol standards, see the International Telecommunication Union Web site.
For more information about Terminal Services, see this Microsoft Web site. The following list shows where to find specific information at this Web site:
- To create and deploy scriptable virtual channels, see "Scriptable Virtual Channels" and "Implementing Scriptable Virtual Channels Using Remote Desktop Web Connection".
- For information about virtual channel naming restrictions, see "Virtual Channel Client Registration".
- For information about storing store the name of the client DLL in the registry, see "Virtual Channel Client Registration".
See Also
RDP Application Development | Remote Desktop Protocol | RDP OS Design Development | Thin Client Overview | How to Develop a Thin Client
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