Introduction

The modern business environment is characterized by pervasive use of computer and communication technologies. Corporations increasingly depend on such technologies to remain competitive in the global economy. Customer relationship management, enterprise resource planning, and electronic mail are just a few of the many applications that generate new data every day. All that data must be stored, managed, and accessed effectively if a business is to survive. This is one of the primary business challenges in the information age, and storage networking is a crucial component of the solution.

Objectives

This book has four objectives: document details, explain concepts, dispel misconceptions, and compare protocols. The details of the major protocol suites are documented for reference. To that end, this book aims primarily to disclose rather than assess. In that respect, we give extra effort to objectivity. Additionally, I attempt to explain how each of the major protocol suites operates, and to identify common understandings. Discussions of how the protocols work are included, but you are encouraged to reference the original standards and specifications for a complete understanding of each protocol. This recommendation also ensures you have the latest information. Since many of the standards and specifications referenced in this book are draft versions, they are subject to change. Thus, it is reasonable to expect some of the content in this book will become inaccurate as in-progress specifications are finalized. Finally, comparisons are drawn between the major protocol suites to help you understand the implications of your network design choices. To achieve these objectives, a large amount of reference data must be included. However, this book is written so that you can read it from cover to cover. We have tried to integrate reference data so it is easily and quickly accessible. For this reason, I use tables and bulleted lists extensively.

In support of the stated objectives, we have made every effort to improve clarity. Colloquialisms are avoided throughout the book. Moreover, special attention is paid to the use of the words may, might, must, and should. The word may implies permissibility. The word might implies possibility. The word must imposes a requirement. The word should implies a desirable behavior but does not impose a requirement.

Intended Audiences

This book has two primary audiences. The first audience includes storage administrators who need to learn more about networking. We have included much networking history, and have explained many networking concepts to help acclimate storage administrators to the world of networking. The second audience includes network administrators who need to learn more about storage. This book examines networking technologies in the context of SCSI so that network administrators can fully understand the network requirements imposed by open systems storage applications. Many storage concepts, terms, and technologies exist that network administrators need to know and understand. Although this book provides some storage knowledge for network administrators, other resources should be consulted for a full understanding of storage. One such resource is Storage Networking Fundamentals: An Introduction to Storage Devices, Subsystems, Applications, Management, and File Systems (by Marc Farley, ISBN: 1-58705-162-1, Cisco Press).

Organization

This book discusses and compares the networking protocols that underlie modern open systems, block-oriented storage networks. To facilitate a methodical analysis, the book is divided into three parts. The first part introduces readers to the field of storage networking and the Open Systems Interconnection (OSI) reference model. The second part examines in detail each of the major protocol suites layer-by-layer beginning with the lowest layer of the OSI reference model. The third part introduces readers to several advanced networking topics. As the book progresses, each chapter builds upon the previous chapters. Thus, you will benefit most by reading this book from front to back. However, all chapters can be leveraged in any order for reference material. Some of the content in this book is based upon emerging standards and in-progress specifications. Thus, you are encouraged to consult the latest version of in-progress specifications for recent updates and changes.