Autorentext

Priscilla Oppenheimer has been developing data communications and networking systems since 1980 when she earned her master’s degree in information science from the University of Michigan. After many years as a software developer, she became a technical instructor and training developer and has taught more than 3000 network engineers from most of the Fortune 500 companies. Her employment at such companies as Apple Computer, Network General, and Cisco gave her a chance to troubleshoot real-world network design problems and the opportunity to develop a practical methodology for enterprise network design. Priscilla was one of the developers of the Cisco Internetwork Design course and the creator of the Designing Cisco Networks course. Priscilla teaches network design, configuration, and troubleshooting around the world and practices what she preaches in her network consulting business.

Klappentext

Network usage is continuing to accelerate as enterprise network users communicate via video-conferencing, develop products more collaboratively, and rely more heavily on networked tools. Top-Down Network Design, Third Edition presents a systematic, fully practical approach to designing networks that will keep pace with these changes. Thoroughly updated for today's newest technical and business trends, it covers all facets of enterprise network design and all elements of modern enterprise networks. The authors' innovative top-down approach starts by focusing on applications and user requirements, and only then turns to technology selection. Readers will discover how to systematically analyze business and technical requirements, and then select topologies and technologies that reflect this analysis. The authors walk through designing campus networks, data centers, remote access, and wide-area connectivity, and designing for security in an era of wireless networks and mobile users. They also present detailed coverage of performance, reliability, and scalability. Graphics are used extensively throughout to clarify concepts and present examples This Third Edition includes new coverage of designing networks that comply with IT Service Management processes, as well as an updated glossary. It also adds chapter-ending essay questions and design scenarios for readers who want to test their understanding of key concepts.

Zusammenfassung

Objectives

The purpose of Top-Down Network Design, Third Edition, is to help you design networks that meet a customer’s business and technical goals. Whether your customer is another department within your own company or an external client, this book provides you with tested processes and tools to help you understand traffic flow, protocol behavior, and internetworking technologies. After completing this book, you will be equipped to design enterprise networks that meet a customer’s requirements for functionality, capacity, performance, availability, scalability, affordability, security, and manageability.

Audience

This book is for you if you are an internetworking professional responsible for designing and maintaining medium- to large-sized enterprise networks. If you are a network engineer, architect, or technician who has a working knowledge of network protocols and technologies, this book will provide you with practical advice on applying your knowledge to internetwork design.

This book also includes useful information for consultants, systems engineers, and sales engineers who design corporate networks for clients. In the fast-paced presales environment of many systems engineers, it often is difficult to slow down and insist on a top-down, structured systems analysis approach. Wherever possible, this book includes shortcuts and assumptions that can be made to speed up the network design process.

Finally, this book is useful for undergraduate and graduate students in computer science and information technology disciplines. Students who have taken one or two courses in networking theory will find Top-Down Network Design, Third Edition, an approachable introduction to the engineering and business issues related to developing real-world networks that solve typical business problems.

Changes for the Third Edition

Networks have changed in many ways since the second edition was published. Many legacy technologies have disappeared and are no longer covered in the book. In addition, modern networks have become multifaceted, providing support for numerous bandwidth-hungry applications and a variety of devices, ranging from smart phones to tablet PCs to high-end servers. Modern users expect the network to be available all the time, from any device, and to let them securely collaborate with coworkers, friends, and family. Networks today support voice, video, high-definition TV, desktop sharing, virtual meetings, online training, virtual reality, and applications that we can’t even imagine that brilliant college students are busily creating in their dorm rooms.

As applications rapidly change and put more demand on networks, the need to teach a systematic approach to network design is even more important than ever. With that need in mind, the third edition has been retooled to make it an ideal textbook for college students. The third edition features review questions and design scenarios at the end of each chapter to help students learn top-down network design.

To address new demands on modern networks, the third edition of Top-Down Network Design also has updated material on the following topics:

¿ Network redundancy

¿ Modularity in network designs

¿ The Cisco SAFE security reference architecture

¿ The Rapid Spanning Tree Protocol (RSTP)

¿ Internet Protocol version 6 (IPv6)

¿ Ethernet scalability options, including 10-Gbps Ethernet and Metro Ethernet

¿ Network design and management tools

Inhalt

Introduction

Part I Identifying Your Customer's Needs and Goals

Chapter 1 Analyzing Business Goals and Constraints 3

Using a Top-Down Network Design Methodology 3

Using a Structured Network Design Process 5

Systems Development Life Cycles 6

Plan Design Implement Operate Optimize (PDIOO) Network Life Cycle 7

Analyzing Business Goals 8

Working with Your Client 8

Changes in Enterprise Networks 10

Networks Must Make Business Sense 10

Networks Offer a Service 11

The Need to Support Mobile Users 12

The Importance of Network Security and Resiliency 12

Typical Network Design Business Goals 13

Identifying the Scope of a Network Design Project 14

Identifying a Customer's Network Applications 16

Analyzing Business Constraints 19

Politics and Policies 19

Budgetary and Staffing Constraints 20

Project Scheduling 21

Business Goals Checklist 22

Summary 23

Review Questions 23

Design Scenario 24

Chapter 2 Analyzing Technical Goals and Tradeoffs 25

Scalability 25

Planning for Expansion 26

Expanding Access to Data 26

Constraints on Scalability 27

Availability 27

Disaster Recovery 28

Specifying Availability Requirements 29

Five Nines Availability 30

The Cost of Downtime 31

Mean Time Between Failure and Mean Time to Repair 31

Network Performance 32

Network Performance Definitions 33

Optimum Network Utilization 34

Throughput 35

Throughput of Internetworking Devices 36

Application Layer Throughput 37

Accuracy 38

Efficiency 39

Delay and Delay Variation 40

Causes of Delay 41

Delay Variation 43

Response Time 44

Security 44

Identifying Network Assets 45

Analyzing Security Risks 46

Reconnaissance Attacks 47

Denial-of-Service Attacks 48

Developing Security Requirements 48

Manageability 49

Usability 50

Adaptability 50

Affordability 51

Making Network Design Tradeoffs 52

Technical Goals Checklist 54

Summary 55

Review Questions 56

Design Scenario 56

Chapter 3 Characterizing the Existing Internetwork 59

Characterizing the Network Infrastructure 59

Develop…