Intranet Journal
The online resource for intranet professionals

Three-Tier Architecture Improves AS/400-To-Web Intranet Performance

Introduction
Expanding beyond the corporate network
An entirely different architecture
Advantages of Microsoft Technologies
Templates simplify GUI development
Advantages of scripting
Wide range of potential applications

The innovation of a three-tier architecture based on Microsoft COM+ technology can dramatically improve AS/400 host-to-intranet performance, easily scaling to 2500 simultaneous users. The traditional approach to delivering AS/400 applications over an intranet is a two-tier architecture in which the Web server runs on the host platform. The new approach uses the following three tiers: 1) a client running on the PC attached to an intranet or the Internet 2) the server represented by the AS/400 and 3) the middle tier running on a Windows NT/2000 box hosted by Internet Information Server (IIS) that handles the communication between client and server layers. This methodology delivers higher performance because each tier can focus exclusively on its assigned task and the critical middle tier can be inexpensively scaled to virtually any level of users simply by adding inexpensive industry-standard computing resources at the middle tier level.

The traditional approach to increasing access to AS/400 applications has been to use graphic user interface (GUI) development tools to transform existing green screens so they look and function like Windows programs. These tools allow developers to quickly attach a friendlier graphical interface to an AS/400 application and provide access from a personal computer through a local or wide area network connection. They provide large advantages to companies that want to make the AS/400 interface more user-friendly and provide access to users from PCs. They also give developers the opportunity to easily convert AS/400 applications to the Windows environment.

About the Author

Karen Bass has an extensive background in PC hardware, AS/400 and PC-LAN products along with other Windows based products. She is experienced in both "hands-on" training and coaching as well as producing problem/ solution manuals for end-users including Mobil Chemical, IBM, Xerox and Kodak. Additionally, Karen has installed and maintained various software packages on a variety of platforms along with providing technical support and implementing a help desk to support over 100 users. Ms. Bass graduated Magna Cum Laude from the Virginia Commonwealth University with a degree in Business Education. She has been published in the National Speakers' Association magazine Professional Speaker.