Understanding Thin-Client/Server Computing
Joel P. Kanter
Published by Microsoft Press
A Division of Microsoft Corporation
One Microsoft Way
Redmond, Washington 98052-6399
Copyright © 1998 by Citrix Systems, Inc.
All rights reserved. No part of the contents of this book may be reproduced or transmitted in any form or by any means without the written permission of the publisher.
Library of Congress Cataloging-in-Publication Data
Understanding Thin-Client/Server Computing / Joel Kanter.
1. Client/server computing. I. Title. II. Series.
004'.36--dc21 97-31953 CIP
Printed and bound in the United States of America.
1 2 3 4 5 6 7 8 9 WCWC 3 2 1 0 9 8
Distributed to the book trade in Canada by Macmillan of Canada, a division of Canada Publishing Corporation.
A CIP catalogue record for this book is available from the British Library.
Microsoft Press books are available through booksellers and distributors worldwide. For further information about international editions, contact your local Microsoft Corporation office. Or contact Microsoft Press International directly at fax (425) 936-7329. Visit our Web site at mspress.microsoft.com.
Citrix, ICA, and WinFrame are registered trademarks and MultiWin is a trademark of Citrix Systems, Inc. Macintosh is a registered trademark of Apple Computer, Inc. Intel is a registered trademark of Intel Corporation. BackOffice, FoxPro, Microsoft, Microsoft Press, MS-DOS, PowerPoint, Visual Basic, Visual C++, Windows, Windows NT, and Win32 are registered trademarks and ActiveX and Visual J++ are trademarks of Microsoft Corporation. NT is a trademark of Northern Telecom Limited. Java is a trademark of Sun Microsystems, Inc. Other product and company names mentioned herein may be the trademarks of their respective owners.
Companies, names, and/or data used in screens and sample output are fictitious unless otherwise noted.
Acquisitions Editor: Stephen G. Guty
Project Editor: Sally Stickney
Technical Editor: James W. Johnson
When Citrix opened for business in 1989, we envisioned a computing paradigm that would simplify the deployment of enterprise applications and enable universal information access from every conceivable desktop and device. The idea was to empower users while providing centralized application deployment and administration for IS professionals. As a result, our mission to deliver on the thin-client/server computing architecture was under way long before terms like “network computers,” “intranet,” and “total cost of ownership” were popularized.
Today, thousands of organizations with millions of information-hungry users around the world connect to Microsoft Windows–based business-critical applications using Citrix WinFrame thin- client/server system software. The rapid adoption of WinFrame is changing the way IS managers think about enterprise computing and application delivery because thin-client/server computing simplifies the IS application environment, reduces cost of ownership, and increases the value of corporate information. It’s a sim-ple idea that is evolutionary in nature but profound in its benefits.
Thin-client/server computing means that 100 percent of all application execution lives on the server. Users gain universal access to these applications from powerful desktop computers using thin-client software or through truly thin devices such as the Windows-based terminal. Enabling this computing architecture is the Independent Computing Architecture (ICA) protocol, which is an emerging de facto standard for thin-client/server computing. The ICA protocol provides a standard way of exchanging application presentation services between powerful servers and a limitless range of information appliances, with minimal traffic over the network. ICA-based protocol support allows any desktop PC, NetPC, Windows-based terminal, Network Computer, Personal Digital Assistant (PDA), or other information appliance to be part of the mission-critical computing infrastructure. The WinFrame thin-client/server environment, built on Microsoft’s powerful Windows NT Server technology, is the solution that many thousands of IS professionals have already chosen to overcome obstacles to delivering the latest software solutions across the enterprise.
Thin-client/server computing facilitates the immediate deployment of corporate applications, information, and software updates by providing a single point of management on the server. This, in and of itself, allows IS professionals to do their jobs more efficiently and effectively. With thin-client/server computing, IS professionals no longer have to touch every desktop to deploy new applications. Users can access applications from anywhere, but the IS professional administers the server from only one location. And support professionals can use tools built right into the server to provide users with training and technical services.
In addition to simplified management, IS professionals are using the thin-client/server model to deliver applications and solutions anywhere in the enterprise network regardless of bandwidth or type of desktop hardware. As a result, homogeneous desktop hardware and unlimited network bandwidth are no longer on the critical path to deploying mission-critical applications.
As you’ll see in the case studies provided in this book, applica-tion and data security is outstanding. Because application code and corporate data never leave the server, application configurations are secure, corporate information is protected, and data replication is eliminated. In fact, thin-client/server computing is the simplest, most secure way of delivering mission-critical applications . . . period.
Understanding Thin-Client/Server Computing is the first book that offers a detailed look at this innovative approach to delivering Windows-based applications. I first met the author, Joel Kanter, when he was the Academic Programs Manager in Microsoft’s Internet Platform and Tools Division. While he had initially discovered that hardware was a barrier to using the latest software tools for supporting technical curricula, he also recognized that school and university IS managers were stretched to their limits. Actually, we thought Joel was pushing the outer limits of thin-client/server computing when he approached us about using WinFrame for making development tools such as Microsoft Visual Basic and Microsoft Visual C++ available to instructional labs. So we humored him and sent copies of WinFrame to him as well as to Professor Corey Schou at Idaho State University. We were pleasantly surprised when Dr. Schou demonstrated how well Win-Frame worked for his instructional labs, making not only Visual Basic and Visual C++ but also Visual J++ available for various courses. Dr. Schou was even able to leverage some of his legacy hardware equipment. (See the case study about Idaho State University in Chapter 8.)
After Joel left Microsoft, he continued to work with Mark Temple- ton, our Vice President of Marketing, to look at ways for reaching all kinds of businesses, organizations, and individuals with the thin-client/server computing message. The result is this book. We greatly appreciate Joel’s early vision to see the implications of thin-client/server computing, his enthusiasm, and his efforts to make this book possible.
I hope that you use Understanding Thin-Client/Server Computing to help you understand how the thin-client/server computing model can fit with your present computing infrastructure and how it can help you to maximize your IS personnel resources, extend your computing investments, increase network efficiency, and enhance information security. The simplicity of thin-client/server computing can help you take your computing environment and your business even further. And this book will help you begin that process.
Edward I. Iacobucci, Chairman
Citrix Systems, Inc.
Fort Lauderdale, Florida