Preface

First there was the mainframe, the desktop, then the enterprise network. This synthesis has evolved to the point where, as some say, " the computer is the network." But, in fact, we are now entering a quantum change phase in the corporate landscape, whereby "the corporation is the network."

Since the Industrial Revolution, many if not most businesses have been built in the proximity of what can be called channels of goods distribution. Initially cities and/or businesses were built by harbors or rivers. Later they were built close to railroads. Later yet, they were built within easy reach of the highway system. Just the past decade or so, goods-intensive businesses may have placed themselves close to airports.

As we enter the twenty-first century, the corporation is as good as, can be seen as, be identified with, or has the out-reach or the in-reach, which is totally defined by its telecommunications network. Today, the network is the channel of goods distribution.

This book focuses on the establishment of corporate Intranets using state of the art infrastructures. Technology and business imperatives are advancing very rapidly. This book takes a fundamental look at this set of technologies with an eye to educate the corporate planner as to the course of action that will best benefit his or her company.

At the computing level, Intranets are the culmination of an evolution that started with a movement to client/server architectures in lieu of large mainframe computers. This occurred in the early to mid 1990s. Now companies are starting to actually replace proprietary client/server systems with systems based on World Wide Web technology.

A loosely independent but coterminous migration has occurred in the underlying communication infrastructure. Companies have moved from proprietary communication architecture. Companies have moved from proprietary communication architectures to Local Area Network (LAN)-based TCP/IP systems, by the early 1990s. With the emergence of Asynchronous Transfer Mode (ATM) in the mid 1990s, many companies have started to replace the lowest layer of the communication infrastructure, at least at the Intranet backbone level, with ATM, so that the communication stack is either IP over ATM LAN Emulation or Classical IP over ATM. During the late 1990s, the protocol stack may further migrate to Multiprotocol Over ATM or IP Switching. So by the year 2000, the corporate Intranet may well look as follows: HTTP/TCP/IP/MPOA/ATM

This book is a discussion of how such a network would be built, and of the individual components: WWW, MPOA, LANE, ATM, RSVP, NHRP, etc. The book is organized in four parts. Part 1 discusses the computing evolution towards Intranet based technologies. Part 2 covers start of the art communication approaches that can be used in support of Intranets. Part 3 covers evolving MPOA based methods for the deployment of Intranets in the later part of the decade.

In Part 1, Chapter 2 provides a description of classical Client/Server systems. Chapter 3 describes the move towards Internet based technologies and Intranets in particular. Chapter 4 describes the WWW principles and related approaches. Chapter 5 wraps up this discussion with a survey of HTML and related technologies.

In Part 2, Chapter 6 provides a primer on ATM technologies. Chapter 7 covers the fundamentals of Quality of Service and how it can be realized on ATM networks.

In Part 3, Chapter 8 sets the ground for the MPOA discussion to follow by describing the "Integrated Services" network model and how it applies to quality of service in Intranets. Chapter 9 provides a detailed discussion of protocols, such as RTP/RTCP/RTSP, used when building real-time networks. Finally, Chapter 10 describes the Resource Reservation Protocol (RSVP).

In Part 4, Chapter 11 lays the foundation for the discussion of migrating to a Multiprotocol Over ATM network by describing the two underlying protocols, LANE and Classical IP over ATM. Chapter 12 then details the MPOA model and its integration with the Next Hop Resolution Protocol (NHRP). Finally, Chapter 13 discusses migration strategies used to build MPOA networks and the existing alternative technologies.