Printer redirection was a new feature in Windows 2000. Terminal Server clients use this feature to redirect print jobs in a TS session to the printers on the client. This means that data printed in a Terminal Server session is printed on the local printer of the user’s computer, even though the job was printed in a session on the Terminal Server. Therefore, clients receive printed output from their session regardless of whether the Terminal Server and the client are physically located in the same city—or even the same country. For example, suppose you have users who live and work in Dallas and use a Terminal Server farm in Redmond, Washington to gain access to applications and tools for their jobs. If these users need to print output from these applications and tools in their sessions, it would be extremely difficult to determine the incoming connection’s physical location and then make a network printer connection back to a printing device that was shared at the client site. If users are mobile or if they sometimes work from home, this task becomes even more complex. Local printer redirection solves issues like this very quickly and easily, without requiring any substantial configuration of Terminal Servers to accomplish the goal.
Terminal Server local printer redirection in Windows 2000 allows clients to see and use that local printer in remote terminal server sessions. The clients must have supported printer hardware that is connected directly to their client machine by a serial, parallel, or USB port. Clients that meet these criteria can print from Terminal Servers in physically distant locations and still receive their output at the same physical location where they are accessing the Terminal Server.
To use local printer redirection, applications must be written to use print to queues rather than physical local ports. Applications that require direct access to physical ports, such as LPT or PRN ports, cannot use this feature. The local port redirection feature in RDP 5.1 should meet the needs of these legacy applications.
Standards and Additional Reading
The following documents provide additional information about Windows 2000 Terminal Services implementations:
Terminal Services Capacity and Scaling White Paper: http://www.microsoft.com/windows2000/techinfo/administration/terminal/tscaling.asp
Chapter 16 of the Windows 2000 Server Resource Kit – Deploying Terminal Services: http://www.microsoft.com/technet/treeview/default.asp?url=/TechNet/prodtechnol/windows2000serv/reskit/deploy/part4/chapt-16.asp
A list of known applications that require modification to run correctly on Terminal Services can be found at:
Remote Desktop Protocol (RDP) is the native presentation protocol for Microsoft® Windows NT® Server 4.0, Terminal Server Edition and Microsoft® Windows® 2000 Terminal Services. 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. RDP 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.
RDP version 5.0 has the following key features:
Configuration for any environment that allows network localization, automatic disconnect, and remote configuration.
Support for three levels of encryption.
Variable bandwidth allocation through client-side bitmap caching and optional compression for low-bandwidth connections, significantly improving performance over low-bandwidth connections.
Roaming disconnect that allows a user to disconnect from a Terminal Services session without logging off or being logged off.
Multichannel-capable protocol that permits separate Virtual Channels for carrying presentation data, serial-device communication (keyboard and mouse), licensing information, and heavily encrypted data.
Multipoint data delivery that allows data from an application to be delivered to multiple parties without having to send the same data to each session individually.
Remote control that 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.
Copy-and-paste capability between the remote session and the local computer.
Common clipboard for simple data exchange.
Local printer redirection so server applications can print locally to the client device.
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 and Microsoft Windows CE .NET use RDP 5.1. Local printer redirection as discussed in this white paper is available only with Windows 2000 Terminal Server and later.
The Terminal Services RDP 5.0 client is available on the web at the following location: