The World of Thin-Client

When I decided to write about thin-client technology, I first tried using the metaphor of Tolkien’s Lord of the Rings. After explaining thin-client with the help of elves, dwarfs, etc., I asked an associate to read my description. I was sure she would return with a clear understanding of Citrix and browser. Instead, she came back lost in the complex relationships I had created between the various characters. That meant deleting a truly classic tale and starting over with the setting moved to the modern world – ho hum. So while this will not be nearly as much fun, I am hopeful it will help you understand the notion of thin-client and what it can and cannot do for your organization.

Thin-client technology is essentially a return to the concept of computing prior to the personal computer. The previous environment, which I will refer to as the “Legacy” environment, was characterized by a single large computer (a mainframe) at headquarters managed by the data processing department. Users were provided with a terminal device (this amounted to a display and a keyboard), typically referred to as a CRT, which connected to the mainframe over a data network. The CRT was often called a “dumb terminal” because it had no ability to process information – its only functions were to display information and allow entry of data with a keyboard.

CIOs loved this environment because they could more easily control a single computer, with a single operating system, and a single version of software running on it. Users generally disliked the technology because they were not able to control the processing of information.

Along came the PC, and the world of a single, controllable computer environment ended. The CIO’s easily managed dream environment of one intelligent device driving hundreds or thousands of dumb terminals turned into a nightmare, with hundreds or thousands of intelligent devices interconnected with a network. Costs went up, reliability went down, and the CIO and users were all dissatisfied.

Thin-client is an attempt to utilize the good points of both the Legacy and PC environments. Many people are confused by thin-client because there are two competing flavors of this technology – Citrix and browser. What is even more confusing is that either can be used individually, both can be used simultaneously, and they can coexist with an existing networked PC environment. Let me discuss each environment.

The Citrix Environment

When technologists currently talk thin-client, they are often referring to a specific technology known as Citrix. The roots of Citrix technology are in an older Unix environment called X-Windows, which essentially created the ability to have graphical Windows-like dumb terminals.

Citrix manages the keyboard input and information displayed on your monitor. It performs more efficiently by minimizing the information that is sent from the keyboard to the computer and then displayed on the monitor. Citrix accomplishes this task by only moving information that has changed back and forth from the computer. For example, if you change one character on your display, only that single character is transmitted to the computer and back to the display. Utilization of this concept dramatically reduces the amount of information flowing among the display, the keyboard, and the remote computer. Candidly, most banking vendors elected to utilize Citrix a few years back only after they realized that the new, network-hogging client/server applications were slowing bank networks to a crawl.

Citrix will run everything and manage the many displays by only moving information that has changed. The key is that the remote display device does not require a complete PC to function. The new dumb terminal is often referred to as a WinTerm.

Citrix environments have several advantages, which include:

• Existing software products can operate in a Citrix environment.
• User terminals can be a mixture of PCs and dumb terminals, thus reducing the need for frequent and costly PC upgrades.
• High speed networks may not be required.

Conversely, the disadvantages include:

• Cost of purchasing and operating Citrix.
• Occasional incompatibility of an application. Our banks that run Citrix frequently need to tweak applications for them to run effectively in this environment.

The Browser Environment

The other thin-client environment is a browser environment. You see this any time you are “surfing” the Internet. Web services are now readily provided within your own bank or by a third party. Development tools have improved, and virtually all newly developed application products are Web enabled.

As in a Citrix environment, in a browser environment a single computer (a Web server) is used to provide processing for a large number of browser-based terminals. Keyboard inputs and mouse movements are transmitted to the Web server, and results are displayed on the browser using a standard language called HTML (HyperText Markup Language).

The big differences between Citrix and browser are these:

1. The user device must be running some type of Web browser.
2. Web servers are not attempting to minimize information sent to and from the user terminal.

Some advantages of a browser environment include:

• Any device capable of running a browser can be a user terminal. This includes PCs, Macintosh, WinTerm, etc.
• Any device connected to the Internet can potentially communicate with a Web server.

Conversely, disadvantages include:

• Existing applications must be rewritten (or a browser interface placed in front of the application) to take advantage of a browser.
• Networks may need to be beefed up due to the higher amounts of information moving between the user and the Web server.
• Some banking functionality may be difficult to provide in a browser environment. The most common example is the lack of “store and forward” capabilities in a teller application. If a branch network goes down, a thin browser is useless to process transactions.

It is entirely possible to operate both a Citrix and a browser environment at the same time, and Gonzo predicts that most of our banks will run mixed environments for several years. Perhaps this should be called a thin-thin-client environment.

As banks migrate to a thin-client environment, I recommend the following pointers:

1. Browser applications are preferred, but make sure the application is proven. There are a lot of immature Web apps right now.
2. Any application running Citrix requires careful discussion with your CIO. Unless your techies are comfortable running Citrix, shy away from these products.
3. If your bank has a large number of single-purpose workstations (e.g., call center), Citrix can be a workable and cost-effective solution.
4. Be careful transitioning all but the most basic users to a terminal from a PC. Many users (e.g., Finance) will be running applications that need local computer resources.

Hopefully you can now sound like a knowledgeable bytehead when discussing thin-client with your technology folks. Good luck, and remember – I didn’t make you distinguish between elves, dwarfs and Tree People to understand the World of Thin-Client.
-caf