Add features to Windows terminal sessions

Windows NT Server 4.0, Terminal Server Edition is a good product, but it doesn't include all the features you need. I mistakenly reported that Service Pack 4 (SP4) for Terminal Server would add support for locally connected printers to a Terminal Server environment without requiring Windows 2000 (Win2K) or Citrix MetaFrame (see "Terminal Server Grows Up," May 1999). This article prompted a flood of email from people who want advanced features, such as support for client-side printing. This feature didn't appear in SP4, so if you wanted to use devices connected to a client port in a Terminal Server session, you had three options:

  • Share devices connected to client ports with the network, and connect to the device from the network.
  • Install MetaFrame 1.0 or 1.8.
  • Install Win2K Server when Microsoft releases it.

Each option was inadequate for many people. In April, another option appeared: NCD ThinPATH Plus. This product is a free add-on to Terminal Server that gives multiuser NT 4.0 support for using local COM, LPT, and Universal Serial Bus (USB) ports from terminal servers and adds sound to the terminal server environment. NCD ThinPATH Plus doesn't do everything that MetaFrame or Win2K does, and this application requires NCD ThinSTAR terminals or PCs, but overall it's pretty cool—and the price is right. (For more information about NCD ThinSTAR terminals, see the sidebar "The NCD ThinSTAR 300," page 148, and "ThinSTAR 200 Windows-based Terminal," November 1998.)

NCD ThinPATH Plus
NCD ThinPATH Plus works on the RDP platform to support client-side sound and peripheral devices. The product combines serverside and client-side software to manage support and make local I/O ports work.

NCD ThinPATH Plus includes three CD-ROMs: Client Services software, Support for ThinSTAR 200 and ThinSTAR 300 terminals, and PC client software. Installing the software is cumbersome because of the pieces involved, but not difficult.

To set up the server, you install Terminal Server and Client Services on the terminal server. The only problem I encountered when I installed the Client Services on a Terminal Server machine was that the service failed to start. However, when I manually started the service from the Services applet in Control Panel, the service worked and caused no problems with other terminal services.

To support NCD ThinSTAR clients, you must run Setup for the NCD ThinSTAR client on an NT server running the NCD ThinSTAR Management Service (TMS), a program required to update the flash memory in NCD ThinSTAR 200 and 300 terminals. This TMS server doesn't have to be a terminal server, but the server must be on the same subnet as the terminals it's updating (each terminal will identify the TMS server by name or IP address on the Management tab of the terminal's local configuration settings). After you've set up the TMS server and installed the NCD ThinSTAR support software, cycle the power to the terminals. When you restart the terminals, they'll copy all the updated files they need from the TMS server to their flash memory.

To set up PC clients, run Setup from the PC client software CD-ROM, which you can either run from the PC or share with the network. I found the NCD ThinSTAR client preparation to be trouble-free, but I ran into one glitch with the PC client software installation. The Setup program has the usual look of a setup wizard with Back and Next buttons, but the program jumps immediately to where the system installs the client setup in C:\windows\system\ncdpcclientservices. You can't change this option, so the program forces you to clutter your system folders.

Using the New Features
You don't have to do anything special to make an NCD ThinSTAR terminal support sound. When you start a session from the Windows-based terminal (WBT), small speakers in the front of the device run the sound scheme you've set up for that client. These speakers are quiet, even at full volume. However, they're adequate, and if you need louder sound support you can plug speakers into the terminal's speaker port. The server doesn't need to use sound—it doesn't have a sound card or speakers.

In contrast, the default sound setting on a PC is off. To use sound, you must enable sound support on the client. To enable the sound and local port mappings, open the NCD ThinPATH Plus controls in the client's Control Panel, as Screen 1, page 149, shows. After you've enabled and disabled the options as appropriate, you will hear sound. You can have two sound systems in place at a time: one for the local client desktop, and one for the terminal server session.

Setting up local ports requires more preparation than setting up sound. On the server side, you must map a virtual printer port to a terminal server port. Run the NCD Client Services tool from the Administrative Tools menu. You'll see a list of virtual COM and LPT ports, as Screen 2 shows. Select the port you want to configure, and click Edit Port. You can edit either virtual or physical ports, but be aware that when you edit a physical port, all output that the terminal server sends to that port will go to the client's printer. Finally, specify whether the printer needs to be available to one or all terminal users. On the client side, connect the printer to the client, restart the client device, set up the printer, and select whether to share the printer with the network.

Finally, NCD ThinPATH Plus adds new Performance Monitor counters. These counters keep track of session activity and terminal server activity.

Sound and Local Port Performance
Installing and configuring sound and local ports is easy, but how does the NCD ThinSTAR perform? When I use the NCD ThinSTAR 300 with only Terminal Server (i.e., without NCD ThinPATH Plus installed) over a 10Base-T network, the NCD ThinSTAR is similar to a PC. However, with NCD ThinPATH Plus, the client session feels sluggish. The performance isn't sluggish on the server side, but when you're typing on the client, the output has to catch up, which makes the client uncomfortable to work with.

The sound is also a little jerky. For Windows sound schemes, the sound is fine—by the time you notice that the sound is a bit choppy, the .wav file has finished playing. However, prolonged sound bites won't sound good. Sound isn't a concern with only NCD ThinPATH Plus, however. I found the same problem when I reviewed MetaFrame 1.0 (for information about MetaFrame 1.0, see "3 Ways to Be Thin," May 1999). The problem is that although TCP/IP (the transport protocol used with RDP) is better for audio or video streaming than more bursty transport protocols such as IPX/SPX, the data flow still isn't perfectly smooth with any protocol. At this point, you can get sound with terminal server sessions, but don't expect to play high-fidelity versions of The Marriage of Figaro. (You can't listen to a CD-ROM anyway because Terminal Server's CD-ROM player doesn't work in RDP terminal server sessions, even with NCD ThinPATH Plus installed. And, the NCD ThinSTAR is a typical WBT that lacks storage media, so the NCD ThinSTAR doesn't have a CD-ROM.)

Network Performance
Before you install support for client-side devices, consider how these devices will affect network performance. For example, according to NCD, NCD ThinPATH Plus supports scanners, but scanners are problematic in a Terminal Server environment because of the amount of communication required between the terminal client, the terminal server, and the scanner attached to the client-side device. This communication will consume a lot of network bandwidth.

When printing, the Terminal Server sessions send print jobs in RAW format, which also consumes network bandwidth. On a LAN without too much print activity, this consumption doesn't present a problem, but larger print jobs, slow WAN links, or a lot of printers will take a long time to print and delay terminal session refreshes.

You'll find this problem not only with NCD ThinPATH Plus but also with printing to a client-side printer in a Terminal Server environment. MetaFrame users will have the same problem.

Should You Consider It?
One new development makes the decision whether to use NCD ThinPATH Plus much easier—you can now download the product for free from NCD's Web site, so you can try the product virtually risk-free. Consider the product if you need to use local COM, USB, or LPT ports for printing or other tasks (e.g., a barcode reader), but don't download it solely for sound.

Win2K supports only client-side LPT ports, so NCD ThinPATH Plus offers functionality that you can't get with an OS upgrade (for more information about running NCD ThinPATH Plus with Win2K, see the sidebar "Win2K and NCD ThinPATH Plus"). Setting up the service was simple, and the port mappings worked the first time without trouble.

You can easily set up a printer or other client-side port device for personal use or to share with other terminal server users. Although using client-side devices might add some strain to your network's bandwidth, NCD ThinPATH Plus is a good product to consider if you need the support.

NCD ThinPATH Plus
Contact: Network Computing Devices * 650-694-0650 or 800-800-9599
Web: http://www.ncd.com
Price: Free
System Requirements: Windows NT Server 4.0, Terminal Server Edition, NCD ThinSTAR Management Service installed on an NT server, Client software installed on PC or terminal clients, NCD ThinSTAR 200 or 300 Windows-based terminals, Client PCs follow Terminal Server requirements