Return of the Thin Client

System builders are always looking for ways to expand their business, and one way of doing this is to meet a wider variety of customer needs. In this Recipe, we'll see how to install and configure Microsoft's Terminal Services and set it up to run applications across a network to thin-client PCs. By offering Windows Terminal Services expertise to larger businesses and their IT managers, system builders will be in a position to earn new customers and leverage the potential for greater revenue streams.

Running applications across a network to terminals from a dedicated computer is an old idea. Ever since the mainframe and the PC began to share the IT environment, businesses have wrestled with different degrees of centralization and decentralization of their computing resources. But with Terminal Server this old idea has a new extension on life.

In simplest terms, Microsoft's Windows Terminal Server lets users run Windows-based applications on a remote computer. One of the main benefits is the ability of IT managers to roll out applications quickly and then maintain them from a centralized computer. So instead of having to install (and update) a Windows application at each desktop computer in the organization, an IT manager can instead deploy the app from the server and updated there as required.

Also, users can rest assured that they are running the most up-to-date version of their application. And support staff has less maintenance issues to worry about. Another benefit of Terminal Server: a reduction in computing power needed at the individual client machine. This directly translates into reduced equipment cost, since nearly any sub-$700 machine will do. It also delivers increased data security; since only the central server handles processing and data storage, there's only one machine to secure.

There are a few challenges to using Terminal Server. Chief among them: keeping up with the demands on the network and the server hardware, while continuing to capitalize on the scalability that the Terminal Server offers. Information security becomes a concern again, with data and applications being stored and run centrally. Also, the cost of licensing Terminal Services can be high, so a system builder should weigh their customers' needs carefully before urging the decision-maker to pursue a centralized model.

Ingredients: Hardware

Here are the hardware components you'll need for this Recipe:

Server: I recommend that you use a dedicated server for your Terminal Services; that way, the load is concentrated on your server when running applications for remote users. You'll want a totally separate machine to run your Terminal Services, apart from your other core business applications such as Web, e-mail or file/print servers. A machine designed for duty as a Terminal Services server should be configured for maximum up-time, with a lot of available CPU power and RAM, and a redundant high-speed network connection.

Here are some basic recommendations for your server:

• Processor: Dual CPU chips, preferably dual-core versions, and 64-bit-capable if needed.
• RAM: At least 2 GB to 4 GB. Going beyond 4 GB requires a 64-bit OS.
• Power: Hot-swappable redundant power supplies.
• Hard Drives: Hot-swappable drives with hot spare available.
• Storage: RAID storage controller with lots of cache and battery backup.
• Network: Dual gigabit Ethernet Network Interface Cards (NICs).
• Other: Remote management capability, for off-hours or off-site monitoring)

These design parameters will give your customer everything they need to keep the Terminal Services machine up and running, even in the event of the most common types of hardware failures. The more client machines that depend on this server for their productivity, the more important this becomes.

Thin Client PCs: The nice thing about running Windows-based applications on a server via Terminal Services is that it's no longer necessary to run the typical Windows OS on the desktop. Without this resource hog, the client machines do not require much RAM. Also, since data storage and application processing are now handled by the server, it is no longer necessary to have permanent storage and a fast CPU chip in the client machines, either. This means the hardware resources required at the network client are dramatically reduced; hence the term "thin client."

For example, you can purchase thin client PC hardware from Hewlett-Packard for about $200 to $700 per system. These thin clients are configured for operating systems such as Windows XP Embedded, Windows CE and Linux.

Another well-known supplier of thin clients is Wyse. The company's hardware, for what it calls "scalable thin computing," covers a similar range of prices and capabilities.