Introduction


The rapidly changing demands of the modern business require a flexible and highly adaptable IT infrastructure. The virtualization of resources plays a key role in achieving the required degree of adaptability. Therefore, the term virtualization is heard in many areas, including the virtualization of servers, applications, storage devices, security appliances, and, not surprisingly, the network infrastructure. This book attempts to illustrate the landscape of virtualization architectures, technologies, and techniques pertinent to the network infrastructure.

Goals and Methods

The overall goal of this book is to provide the reader with an understanding of what network virtualization is, which problems it can solve, and what techniques are currently available to virtualize the network. The concepts are covered both from a theoretical and practical point of view.

One important goal of this book is to provide an architectural framework for the problem of network virtualization. This framework should allow the reader to better understand the different network virtualization technologies and architectures.

Based on the architectural framework, many technologies are discussed and illustrated through network design examples. The goal of this discussion is to provide the reader with enough information about the technologies and techniques to either use them as presented or creatively implement variations of the proposed designs.

Who Should Read This Book?

This book has been written primarily for enterprise network designers, planners, architects, operators, and support personnel. These are the people responsible for the support, design, and deployment of network services; and they will find the topic, scope, and level of detail beneficial, whether they are looking at understanding virtualization's effect on enterprise networks, deploying segmented networks, shared services or just migrating from a legacy transport infrastructure, such as Frame Relay or ATM.

This book is also of interest to the user and purchaser of enterprise networks, including IT and telecom consultants and directors and CIOs or CTOs in small, medium-size, and large enterprises and network engineers and support staff. Technical sales personnel both at network vendors and their integration partners will also greatly benefit from this book.

How This Book Is Organized

Although this book could be read cover to cover, it is designed to be flexible and allow you to easily move between chapters and sections of chapters to cover just the material that you need more work with. The book is organized into three sections. Part I reviews the business imperatives driving network virtualization, reviews enterprise network design best practices, and introduces the basic technology and architectures used in virtualized networks today. Part II is the core of the book and discusses how to design virtualized networks in the core, across the WAN, in the data center, and in the access layer.

Part III is the appendix section, which has supplemental information for topics that might be less familiar to readers with an enterprise background and a collection of reference material.

  • Chapter 1, "Business Drivers Behind Enterprise Network Virtualization" The nature of business continues to evolve, and in great part, this evolution depends on the advent of new technologies that allow unprecedented levels of communication and collaboration. This chapter takes a close look at how virtualized networks can support optimized business processes to the extent of enabling revolutionary process changes, which would have been costly and diffi-cult to implement without the appropriate enabling technology.

  • Chapter 2, "Designing Scalable Enterprise Networks" This chapter describes the fundamental principles on which highly available, scalable enterprise networks are designed. These principles are the foundation of good network design and must be maintained as the network is virtualized.

  • Chapter 3, "A Basic Virtualized Enterprise" In this chapter, the basic elements of a virtualized enterprise network are introduced. An architectural framework is proposed to break down the problem of virtualization. The framework is made of functional areas that are the building blocks of a virtualized network architecture.

  • Chapter 4, "A Virtualization Technologies Primer: Theory" There are different levels of virtualization: device, data path, and control plane. There are different constructs and protocols to implement each of these, depending on the problem to be solved. This chapter covers the technology used to build virtualized networks, including virtual partitions on routers and switches and protocol extensions.

  • Chapter 5, "Infrastructure Segmentation Architectures: Theory" This chapter brings together the technologies introduced in the previous chapter in several architectures for network virtualization. The alternatives covered are tunnel overlay for Layer 2 and Layer 3 transport, RFC 2547, and hierarchical Layer 3 VPN.

  • Chapter 6, "Infrastructure Segmentation Architectures: Practice" The concepts discussed in the previous chapters are put in practice in this chapter. The subtleties of the implementation of the different technologies and architectures are analyzed in the context of the campus and metropolitan-area network.

  • Chapter 7, "Extending the Virtualized Enterprise over the WAN" The use of the virtualization technologies and architectures in the WAN poses unique challenges. In this chapter, we explore the challeneges and best practices for the extension of virtualized networks over the WAN.

  • Chapter 8, "Traffic Steering and Service Centralization" In this chapter, we explore the different methods for sharing and centralizing services among different virtual networks.

  • Chapter 9, "Multicast in a Virtualized Environment" A virtualized enterprise network is fully capable of carrying multicast traffic. This chapter discusses how to carry multicast data in a virtualized network environment. There are two main transport architectures: point-to-point and multicast VPN. We examine each in turn, with a discussion of the design trade-offs and an example to show the basic configuration steps involved.

  • Chapter 10, "Quality of Service in a Virtualized Environment" This chapter focuses on quality of service mechanisms available in virtualized networks and discusses deployment considerations. This chapter discusses the traditional enterprise QoS model, but also MPLS traffic engineering and differentiated services-aware traffic engineering, which are two powerful applications available on virtualized networks.

  • Chapter 11, "The Virtualized Access Layer" This chapter covers virtualized access layer design. The major impact of virtualization concerns authentication and authorization, and this chapter discusses clientless and client-based methods, notably 802.1x. A design example is provided to show how to implement network policy at the access layer and how to interact with the rest of the virtualized network.

  • Appendix A, "L2TPv3 Expanded Coverage" Additional information on the Layer 2 Tunnel Protocol Version 3 (L2TPv3), introduced in Chapter 4.

  • Appendix B, "MPLS QoS, TE, and Guaranteed Bandwidth" In-depth explanation of MPLS QoS mechanisms and MPLS traffic engineering and MPLS guaranteed bandwidth. This appendix is additional content for Chapter 10.

  • Appendix C, "Recommended Reading" This appendix lists documents used during the preparation of this book and additional sources of information for the interested reader.

  • Appendix D, "RFCs and Internet Drafts" Relevant RFC and Internet drafts for the technologies and architectures covered in this book.




Network Virtualization
Network Virtualization
ISBN: 1587052482
EAN: 2147483647
Year: 2006
Pages: 128

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