Open Menu Close Menu

Windows for Heterogeneous Environments

We have broken away from the tyranny of the mainframe. Ever since the image of liberation offered by the video announcing the Macintosh, a homage to Orwell’s 1984, we have endowed the user with evermore powerful, personal computers. Occasionally a special tool emerges, like the Palm Pilot, which provides personal information management services (PIM). Of course the handheld PIM is being pushed to do more—becoming an MP3 player, a camera, a phone, etc. But the exception proves the rule.

Dumb Terminals
Windows Server or Citrix MetaFrame
Networked Computer
Connected to a mainframe (or in today's terminology a central server) Connected to a server Networked to a server Usually networked to a server
Programs originate & execute on the server Programs originate & execute on server; graphics execute on desktop Programs originate on server & execute on desktop or server Programs usually originate & execute on desktop, but can originate or execute on server

Based on:

Cost, flexibility, complexity, and support costs increase

With independence has come a fair share of problems. We’re finding PC prices dropping only slightly while capacity, capability, and complexity increases exponentially. This shortens the lifespan of PCs. Most of us are replacing desktop systems every three to four years. Recall that in 1999 Intel introduced the 500Mhz Pentium III processor, NVIDIA released the first graphical processing unit (GPU), and the IEEE published the 802.11b wireless protocol. If you’re not replacing your 1999 workhorse PC (see sidebar), your students and faculty are not being served.

Yet you’re still reeling with the cost of support. The complexity of today’s computer classrooms and labs is driving up the costs of integration testing, configuration, and installation. Is there no end to this?

If you prize flexibility then there is no alternative but to provide the environment that is able to support it. It’s costly, but you can run the software you want, configured how you want it. However, if you can find significant areas where standardization is a positive attribute, then deployment of “thin client” computers may work for you.

What’s a Thin Client?
A thin-client computer is stripped down to the basics. It has a network card, processor, video card, and some local memory. The processing is done on the server. Thin clients are built with small, single-chip designs that reduce power consumption, maximize Internet compatibility, and present a simplified, controlled environment for more tractable software integration.

On a thin client all applications actually run on a shared server or group of servers, and are not executed by the client desktop. The client is responsible for managing the screen, keyboard, and mouse information, passed to it by the server, nothing else. Instead, the application server must have software installed on it to manage multiple application sessions corresponding to the sessions users are running.

Centralized applications and processing dramatically reduces the need for hands-on maintenance. Upgrades and profiles are done on the server and automatically deployed to every location with a client connection not by transferring the new upgrades down each client, but enabling all the clients to leverage the server’s upgrade and profiles. The need to touch the installed base of machines is radically reduced. Of course, there are application deployment tools that push out software from applications servers to connected PCs. But the simplicity of the thin client approach makes it unnecessary to push out applications.

Remote Desktops vs. Remote Applications
Running Windows on the server simplifies things considerably. But you still have a choice to make. Are you going to run a full Windows desktop or do you want to run just the applications that matter to you and nothing more? A thin client running a virtual desktop is both the simplest but also least flexible environment. Running applications from a client extends your options since the client can itself be something other than a PC. Why would you do that? One way to break the tyranny of three-year equipment renewal cycles is to extend them. But older PCs don’t run today’s applications. Then again, an older PC acting as a client isn’t running the application, so it lives to work for another day.

Shades of the Mainframe
If this looks familiar, it is. The mainframe has been reborn in server clothing. To run this kind of environment you need the Microsoft Windows 2000 or 2003 application server software at a minimum. Microsoft Windows Server is the foundation for all these Windows thin client options. The limitations of Terminal Services on Windows 2000 Server made it suitable for only the smaller environments where users are accessing full remote desktops. With Windows Server 2003, it’s a more complicated decision.

After having taken the first steps, Microsoft did very little for a long time, leaving creative third parties to develop thin client functionality. In stepped Citrix, Tarantella, and others to provide services, management, and scalability. The boys and girls in Redmond may have been preoccupied but they have returned with studied determination to build a much improved product.

When D'es Thin Client Terminal Services Make Sense?
Thin Clients may be right for you if any of the following are true:
· you are using a limited set of standard MS applications;
· you are not currently running an enterprise-wide managed Windows environment;
· your enterprise is very distributed, with many WAN links;
· your network needs upgrading;
· you have a significant number of client devices nearing replacement.

Figuring out the cost effectiveness of a thin client is no small task. Various vendors have so-called “assessment calculators” to help you categorize your expenses and infrastructure investments (for example, see the Application Computing Environment (ACE) Cost Analyzer by Citrix at

A Sampling of Application Server Environments

Terminal Services for Microsoft Windows Server 2003

Citrix MetaFrame XP Presentation Server 1.0 w/ Feature Release 3

Jetro CockpIT 3.0 / BoostIT 3.0

Tarantella New Moon Canaveral iQ 2.0

DAT Panther Server 2002


While the above conditions may tilt the calculation toward the thin client direction, probably the two most important factors that make thin clients or terminal application environments attractive are: (1) having a significant number of PCs used to run a restricted set of applications, such as MS Office and a few standard Windows programs; (2) having a mixture of clients who need to run critical Windows applications. Either of these two settings may lead you towards at least a small Windows Terminal Services implementation. After that, the ability to be sure a program will run on a variety of client machines after being set up once starts to make you wonder where else it might fit into your enterprise infrastructure.


Thin Clients Gain Momentum, Daniel Robinson March 10, 2003, Resources for the Embedded Windows Community

Thin Clients Fat Savings
Rishi Seth, November 25, 2003,93653.html

Thin Client Tablets

Server-Based Computing Software Roundup
Brian Madden and Gabe Knuth, October 2003

comments powered by Disqus