This is one of three articles (1, 2, 3), in which the author, an UPP consultant, discusses mainframes, intranets, the Internet and World Wide Web, and making it all work for your bottom line.

Intranets: Wave of the Future?
Open any magazine today and you are sure to find something about an intranet and why your company should have one. Most "Internet" companies are actually more interested in the business intranet market rather than its well-known cousin -- the Internet. Industry forecasts predict the intranet market to reach $20 billion by the end of the decade. Of course, the facts must be separated from the hype. Exactly how will an intranet benefit your company? More importantly, what will your end users gain by having access to the company intranet?

Intranets Defined
First, some definitions are required. Exactly, what is an intranet? By exact definition, an intranet consists of two computers connected via a network interface. Typically, this is the Transmission Control Protocol/Internet Protocol, or simply TCP/IP, but that is not required. By practical standards, an intranet consists of at least one World Wide Web (WWW) server accessed via the corporate LAN using TCP/IP. Of course, WWW server may be misleading since two computers communicating across an office is not exactly "World Wide," but this is all that is required for an intranet. While this may be a practical definition, in reality, if your company is using TCP/IP as a network, you have an intranet right now. Of course, you may not be using the applications that one typically associates with the Internet, but the concept is the same.

Business Evolution
Now that we understand what an intranet is, we can ask how and why they are developed. Most intranets evolve in two fashions -- the company establishes a working group to formally coordinate new servers and their content, or employees in the company install and configure their own web servers for everyone to see. Both methods have merit, but the former allows the company to place a common "face" on internal company data. Generally, a policy of co-existence works best where official company information is left to the company intranet administrator and all web pages of a personal nature are clearly marked as such. While the company can enforce a policy of "one voice" for web servers, the basis of the web is the free sharing of ideas. To create a policy to stifle employee creativity will only serve to cause resentment and, most importantly, revolt against the idea of an intranet. Just as a company is only as good as the people it hires, an intranet is only as good as the available data.

What Does That Have Do With Mainframes?
When people think of the intranet, their last thought would be of that old dinosaur affectionately called the mainframe. The fact is that the current family of mainframes sold by Unisys are as open as any UNIX system and much more reliable. To offer mainframe data to the intranet, a method is required to send the data from the mainframe to the end user's web browser. Ultimately, this requires a web server. While there are various ways to approach this, the most desirable is to place the web server directly on the mainframe. This approach sends the actual TCP/IP request from the web browser directly into the mainframe and the response directly back to the browser. Several web servers are available for the A-Series from Unisys and third-parties. Additionally, Unisys includes a web server on both the 2200 and A-Series versions of the Clearpath systems. Once the mainframe has the ability to directly interface to the intranet, the next step is to determine the types of applications to make use of this connection.

Terminal Emulation
One intranet application that can access the mainframe is terminal emulation. Frequently, companies find themselves with multiple desktop environments such as Windows, Macintosh, and UNIX among others. Too often the company settles on an emulator for one environment simply because it is available for most, if not all, of the other environments. In many cases, the company has one vendor for the Macintosh emulators and another vendor for the Windows and UNIX systems. The possibilities for confusion are clear. What if the company could use a single emulator on all desktop platforms? The terminal emulator would run on all systems and be downloaded from the mainframe. Believe it or not, this is possible. All that is required is a common desktop operating system on all systems and a web server. Now, before you discount me as a mad hatter, an operating system does exist that will run on the systems mentioned. This operating system is called Java.

Java: The Virtual Machine
If ever there was a computer term that could be more overused than the "Internet," it's Java. Simply put, Java is a virtual machine (an operating system within an operating system) that allows applications written in the Java language to run on the Java system. The fact that the Java Virtual Machine (JVM) is running on a Macintosh or a Windows PC, or even a Sun system is immaterial. The Java system on the particular workstation is responsible for implementing a standard operating environment that will allow Java applications, or "applets," to run on them. So, in order to continue the idea of a "Universal" terminal, you need a terminal emulation application written in Java. Also required is the virtual machine. Fortunately for this scenario, you may already have a Java virtual machine on your desktop. The good folks at Netscape, Microsoft, Apple, and Sun have implemented the virtual machine in their web browsers. So, if you have Netscape Navigator 3.0 for Windows for example, you already have the required software to run any Java applet. Several companies offer a Java-based terminal which emulates a Unisys T27. As in the web server case, these are implemented either as a PC-Gateway or on the mainframe itself. The same concerns about extra protocol and coordination of messages exist in this PC-Gateway approach. Therefore, mainframe-based Java emulation is preferred. So, with these emulators in hand, you can offer A-Series terminal access from any web browser in the company.

The Role of HTML
Other methods to access the mainframe from a web browser are to have a process "convert" terminal screens to the language of the web -- HTML -- or to create the applications with HTML in mind. It is possible to create a process to accept data from a typical on-line application and convert it into HTML to send to a web browser. Basically, there are two general approaches: PC-gateway based, or mainframe-based. The PC approach sends data from mainframe applications, converts it to HTML on the PC, and uses the PC web server to send data to the web browser. The mainframe approach interfaces directly to the mainframe applications, converts the data to HTML and uses a mainframe-based web server to send data.

Rather than converting terminal screens to HTML, which does not always work quite as anticipated on screens with a lot of fields, you can create applications with HTML in mind. One of the features of some mainframe-based web browsers is the ability to interface with another program running on the same system. If so desired, the mainframe applications could be modified to accept data from the web server in addition to terminals. If the data is sent in from the web server, the proper fields need to be moved to where the program expected the data from the terminal. In this case, the application processes the message according to the same business rules, but instead of sending the message back to the terminal, it responds to the web server. Again, instead of sending form delimiters, the resultant output is formatted in HTML. The web server will send this data to the web browser without conversion. While this method requires more up-front coding, the actual execution time is less since there is no data conversion required.

Summary
Hopefully, you now have an understanding of an intranet and how it can be used in your company. Additionally, after this reading this article, there should be no doubt that once again, the mainframe is still a viable business resource for your entire company. Next month, I will examine some applications to put the mainframe on the actual Internet and allow customers to order products and perform their own customer service inquiries.

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Unisys Mainframe photograph provided by Unisys Corporation.