MPLS-Enabled Applications E-Book

Ina Minei

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch
• Veröffentlichungsjahr: 2010

Seitenzahl: 1085

Beschreibung

With a foreword by Yakov Rekhter "Here at last is a single, all encompassing resource where the myriad applications sharpen into a comprehensible text that first explains the whys and whats of each application before going on to the technical detail of the hows." --Kireeti Kompella, CTO Junos, Juniper Networks The authoritative guide to MPLS, now in its Third edition, fully updated with brand new material! MPLS is now considered the networking technology for carrying all types of network traffic, including voice telephony, real-time video, and data traffic. In MPLS-Enabled Applications, Third Edition, the authors methodically show how MPLS holds the key to network convergence by allowing operators to offer more services over a single physical infrastructure. The Third Edition contains more than 170 illustrations, new chapters, and more coverage, guiding the reader from the basics of the technology, though all its major VPN applications. MPLS Enabled-Applications contains up-to-date coverage of: * The current status and future potential of all major MPLS applications, including L2VPN, L3VPN, pseudowires and VPLS. * A new chapter with up to date coverage of the MPLS transport profile, MPLS-TP. * MPLS in access networks and Seamless MPLS, the new architecture for extending MPLS into the access, discussed in depth for both the unicast and the multicast case. * Extensive coverage of multicast support in L3VPNs (mVPNs), explaining and comparing both the PIM/GRE and the next generation BGP/MPLS solutions, and including a new chapter on advanced topics in next generation multicast VPNs. * A new chapter on advanced protection techniques, including detailed discussion of 50 ms end-to-end service restoration. * Comprehensive coverage of the base technology, as well as the latest IETF drafts, including topics such as pseudowire redundancy, VPLS multihoming, IRB and P2MP pseudowires. MPLS-Enabled Applications will provide those involved in the design and deployment of MPLS systems, as well as those researching the area of MPLS networks, with a thoroughly modern view of how MPLS is transforming the networking world. "Essential new material for those trying to understand the next steps in MPLS." --Adrian Farrel, IETF Routing Area Director "MPLS-Enabled Applications takes a unique and creative approach in explaining MPLS concepts and how they are applied in practice to meet the needs of Enterprise and Service Provider networks. I consistently recommend this book to colleagues in the engineering, education and business community." --Dave Cooper, Chief IP Technologist, Global Crossing Ltd

Leseprobe

Contents

Cover

Endorsement

Half Title

Series

Title Page

Copyright

About the Authors

Foreword

Preface

WHO SHOULD READ THIS BOOK?

WHAT IS NEW IN THE THIRD EDITION?

HOW THIS BOOK IS ORGANIZED

REFERENCES

Acknowledgements

Part One

1: Foundations

1.1 HISTORICAL PERSPECTIVE

1.2 CURRENT TRENDS

1.3 MPLS MECHANISMS

1.4 CONCLUSION

1.5 REFERENCES

1.6 FURTHER READING

1.7 STUDY QUESTIONS

2: Traffic Engineering With MPLS (MPLS-TE)

2.1 INTRODUCTION

2.2 THE BUSINESS DRIVERS

2.3 APPLICATION SCENARIOS

2.4 SETTING UP TRAFFIC-ENGINEERED PATHS USING MPLS-TE

2.5 USING THE TRAFFIC-ENGINEERED PATHS

2.6 DEPLOYMENT CONSIDERATIONS

2.7 USING TRAFFIC ENGINEERING TO ACHIEVE RESOURCE OPTIMIZATION

2.8 OFFLINE PATH COMPUTATION

2.9 CONCLUSION

2.10 REFERENCES

2.11 FURTHER READING

2.12 STUDY QUESTIONS

3: Protection And Restoration In MPLS Networks

3.1 INTRODUCTION

3.2 THE BUSINESS DRIVERS

3.3 FAILURE DETECTION

3.4 END-TO-END PROTECTION

3.5 LOCAL PROTECTION USING FAST REROUTE

3.6 LINK PROTECTION

3.7 NODE PROTECTION

3.8 ADDITIONAL CONSTRAINTS FOR THE COMPUTATION OF THE PROTECTION PATH

3.9 INTERACTION OF END-TO-END PROTECTION AND FAST REROUTE

3.10 DEPLOYMENT CONSIDERATIONS FOR LOCAL PROTECTION MECHANISMS

3.11 IP AND LDP FRR

3.12 CONCLUSION

3.13 REFERENCES

3.14 FURTHER READING

3.15 STUDY QUESTIONS

4: MPLS DiffServ-TE

4.1 INTRODUCTION

4.2 THE BUSINESS DRIVERS

4.3 APPLICATION SCENARIOS

4.4 THE DiffServ-TE SOLUTION

4.5 EXTENDING THE DiffServ-TE SOLUTION WITH MULTICLASS LSPs

4.6 CONCLUSION

4.7 REFERENCES

4.8 FURTHER READING

4.9 STUDY QUESTIONS

5: Interdomain Traffic Engineering

5.1 INTRODUCTION

5.2 THE BUSINESS DRIVERS

5.3 SETTING UP INTERDOMAIN TE LSPs

5.4 INTERPROVIDER CHALLENGES

5.5 COMPARISON OF THE LSP SETUP METHODS

5.6 CONCLUSION

5.7 REFERENCES

5.8 FURTHER READING

5.9 STUDY QUESTIONS

6: MPLS Multicast

6.1 INTRODUCTION

6.2 THE BUSINESS DRIVERS

6.3 P2MP LSP MECHANISMS

6.4 LAN PROCEDURES FOR P2MP LSPs

6.5 COUPLING TRAFFIC INTO A P2MP LSP

6.6 MPLS FAST REROUTE

6.7 INGRESS REDUNDANCY FOR P2MP LSPs

6.8 P2MP LSP HIERARCHY

6.9 APPLICATIONS OF POINT-TO-MULTIPOINT LSPs

6.10 CONCLUSION

6.11 REFERENCES

6.12 STUDY QUESTIONS

Part Two

7: Foundations of Layer 3 BGP/MPLS Virtual Private Networks

7.1 INTRODUCTION

7.2 THE BUSINESS DRIVERS

7.3 THE OVERLAY VPN MODEL

7.4 THE PEER VPN MODEL

7.5 BUILDING THE BGP/MPLS VPN SOLUTION

7.6 BENEFITS OF THE BGP/MPLS VPN SOLUTION

7.7 REFERENCES

7.8 FURTHER READING

7.9 STUDY QUESTIONS

8: Advanced Topics in Layer 3 BGP/MPLS Virtual Private Networks

8.1 INTRODUCTION

8.2 ROUTING BETWEEN CE AND PE

8.3 DIFFERENTIATED VPN TREATMENT IN THE CORE

8.4 ROUTE REFLECTORS AND VPNs

8.5 SCALABILITY DISCUSSION

8.6 CONVERGENCE TIMES IN A VPN NETWORK

8.7 SECURITY ISSUES

8.8 QoS IN A VPN SCENARIO

8.9 IPv6 VPNs

8.10 CONCLUSION

8.11 REFERENCES

8.12 FURTHER READING

8.13 STUDY QUESTIONS

9: Hierarchical and Inter-AS VPNs

9.1 INTRODUCTION

9.2 CARRIERS’ CARRIER – SERVICE PROVIDERS AS VPN CUSTOMERS

9.3 MULTI-AS BACKBONES

9.4 INTERPROVIDER QoS

9.5 CONCLUSION

9.6 REFERENCES

9.7 FURTHER READING

9.8 STUDY QUESTIONS

10: Multicast in a Layer 3 VPN

10.1 INTRODUCTION

10.2 THE BUSINESS DRIVERS

10.3 mVPN – PROBLEM DECOMPOSITION

10.4 THE ORIGINAL MULTICAST SOLUTION − PIM/GRE MVPN (DRAFT-ROSEN)

10.5 NG MULTICAST FOR L3VPN – BGP/MPLS mVPN (NG mVPN)

10.6 COMPARISON OF PIM/GRE AND BGP/MPLS mVPNs

10.7 CONCLUSION

10.8 REFERENCES

10.9 FURTHER READING

10.10 STUDY QUESTIONS

11: Advanced Topics in BGP/MPLS mVPNs

11.1 INTRODUCTION

11.2 BGP/MPLS mVPN – INTER-AS OPERATIONS

11.3 SUPPORT OF PIM DM IN BGP/MPLS mVPN

11.4 DISCOVERING THE RP – AUTO-RP AND BSR SUPPORT IN BGP/MPLS mVPN

11.5 IMPLEMENTING EXTRANETS IN BGP/MPLS mVPN

11.6 TRANSITION FROM DRAFT-ROSEN TO BGP/MPLS mVPNs

11.7 SCALABILITY DISCUSSION

11.8 ACHIEVING MULTICAST HIGH AVAILABILITY WITH BGP/MPLS mVPN

11.9 INTERNET MULTICAST SERVICE USING THE BGP/MPLS mVPN TECHNOLOGY

11.10 CONCLUSION

11.11 REFERENCES

11.12 STUDY QUESTIONS

12: Layer 2 Transport over MPLS

12.1 INTRODUCTION

12.2 THE BUSINESS DRIVERS

12.3 COMPARISON OF LAYER 2 VPNs AND LAYER 3 VPNs

12.4 PRINCIPLES OF LAYER 2 TRANSPORT OVER MPLS

12.5 FORWARDING PLANE

12.6 CONTROL PLANE OPERATION

12.7 ADMISSION CONTROL OF LAYER 2 CONNECTIONS INTO NETWORK

12.8 FAILURE NOTIFICATION MECHANISMS

12.9 MULTI-HOMING

12.10 LAYER 2 INTERWORKING

12.11 CIRCUIT CROSS CONNECT (CCC)

12.12 POINT-TO-MULTIPOINT LAYER 2 TRANSPORT

12.13 OTHER APPLICATIONS OF LAYER 2 TRANSPORT

12.14 CONCLUSION

12.15 REFERENCES

12.16 STUDY QUESTIONS

13: Virtual Private LAN Service

13.1 INTRODUCTION

13.2 THE BUSINESS DRIVERS

13.3 VPLS MECHANISM OVERVIEW

13.4 FORWARDING PLANE MECHANISMS

13.5 CONTROL PLANE MECHANISMS

13.6 LDP AND BGP INTERWORKING FOR VPLS

13.7 INTERPROVIDER OPTION E FOR VPLS

13.8 OPERATIONAL CONSIDERATIONS FOR VPLS

13.9 CONCLUSION

13.10 REFERENCES

13.11 STUDY QUESTIONS

Part Three

14: Advanced Protection and Restoration: Protecting the Service

14.1 INTRODUCTION

14.2 THE BUSINESS DRIVERS

14.3 FAILURE SCENARIOS

14.4 EXISTING SOLUTIONS

14.5 PROTECTING THE EGRESS – LOCAL PROTECTION SOLUTION

14.6 CONCLUSION

14.7 REFERENCES

14.8 FURTHER READING

14.9 STUDY QUESTIONS

15: MPLS Management

15.1 INTRODUCTION

15.2 MANAGEMENT – WHY AND WHAT

15.3 DETECTING AND TROUBLESHOOTING FAILURES

15.4 CONFIGURATION ERRORS

15.5 VISIBILITY

15.6 CONCLUSION

15.7 REFERENCES

15.8 FURTHER READING

15.9 STUDY QUESTIONS

16: MPLS in Access Networks and Seamless MPLS

16.1 INTRODUCTION

16.2 THE BUSINESS DRIVERS

16.3 MODELS FOR MPLS DEPLOYMENT IN ACCESS NETWORKS

16.4 SEAMLESS MPLS MECHANISMS

16.5 CONCLUSIONS

16.6 REFERENCES

16.7 STUDY QUESTIONS

17: MPLS Transport Profile (MPLS-TP)

17.1 INTRODUCTION

17.2 THE BUSINESS DRIVERS

17.3 REQUIREMENTS FOR A TRANSPORT PROFILE FOR MPLS

17.4 MPLS-TP FUNCTIONALITY

17.5 DEPLOYMENT CONSIDERATIONS

17.6 MISCONCEPTIONS ABOUT MPLS-TP

17.7 CONCLUSION

17.8 REFERENCES

17.9 STUDY QUESTIONS

18: Conclusions

18.1 INTRODUCTION

18.2 NETWORK CONVERGENCE

18.3 INTERACTION WITH CLIENT EDGE EQUIPMENT

18.4 INTERPROVIDER CAPABILITY

18.5 MPLS IN THE DATA COMMUNICATIONS NETWORK (DCN)

18.6 MPLS IN MOBILE NETWORKS

18.7 MPLS IN THE ENTERPRISE

18.8 MPLS IN THE TRANSPORT

18.9 FINAL REMARKS

18.10 REFERENCES

Appendix A: Selected Backhaul Scenarios in MPLS-Based Access Networks

A.1 INTRODUCTION

A.2 DATA SERVICES FOR BUSINESS CUSTOMERS

A.3 RESILIENCE CONSIDERATIONS

A.4 xDSL BACKHAUL SCHEMES

A.5 REFERENCES

Appendix B: MPLS Resources

B.1 STANDARDS BODIES

B.2 CONFERENCES

B.3 INTEROPERABILITY TEST LABS

Appendix C: Solutions to Selected Study Questions

CHAPTER 1

CHAPTER 2

CHAPTER 3

CHAPTER 4

CHAPTER 5

CHAPTER 6

CHAPTER 7

CHAPTER 8

CHAPTER 9

CHAPTER 10

CHAPTER 11

CHAPTER 12

CHAPTER 13

CHAPTER 14

CHAPTER 15

CHAPTER 16

CHAPTER 17

Appendix D: Acronyms

Index

‘While MPLS is in itself simple, its apparent complexity lies in the proliferation of applications, which shows no signs of ceasing. To make things worse, catching up involves reading a large number of documents written by various authors at various times in various styles. Here at last is a single, all encompassing resource where the myriad applications sharpen into a comprehensible text that first explains the whys and whats of each application before going on to the technical detail of the hows.’

Kireeti Kompella, CTO Junos, Juniper Networks

‘MPLS-Enabled Applications thoroughly covers the MPLS base technology and applications on MPLS-enabled IP networks. It guides you to a comprehensive understanding of standards, problems, and solutions in networking with MPLS. Before it had been necessary to go through material from many different sources, here we have everything in one place. All the MPLS protocols are covered, as are the applications of these protocols. This should be the textbook for MPLS courses, both for training of experienced networking professionals and for universities.’

Loa Andersson, Ericsson AB and IETF MPLS working group co-chair

‘Although over ten years old, MPLS technology continues to evolve to meet the developing requirements of network operators and the advancing aspirations of network users. It is important that a book like this should continue to be updated in step with the changes to MPLS, and this new revision includes essential new material for those trying to understand the next steps in MPLS.’

Adrian Farrel, IETF Routing Area Director

‘This book continues to be the industry and academic state-of-the-art on explaining the foundation and nuances of MPLS technology. It is extremely well written and tackles all of the most modern extensions of MPLS technology. If you are interested in how the internet works, it will be a well-worn read. It should be on every internet practitioner's bookshelf.’

Dave Ward, IETF WG chair: BFD, Softwires, ISIS, HIP

‘This is the MPLS text that the industry has been waiting for. On one hand, the text presents MPLS technology clearly enough that the reader can absorb its content in a few easy sittings. On the other hand, the text provides a sufficiently in-depth treatment that even an MPLS expert can learn from it. The authors offer a clear and complete description of MPLS, its inner workings and its applications, in a manner that could only be achieved by persons who have been significant contributors to the MPLS development effort. Every network operator who has deployed or is considering the deployment of MPLS technology should read this book. It is appropriate reading for everyone from the CTO to the tier 1 NOC engineer.’

Ron Bonica, Juniper Networks, Co-director IETF Operations and Management Area

‘MPLS-Enabled Applications provides excellent insight on how recently developed solutions can help address challenges for providing multicast in MPLS-based VPNs. The in-depth coverage of recent advances in MPLS technology that provide multicast support in L2 and L3 VPNs is essential to anyone needing to deploy both basic use cases and advanced scenarios as well.’

Thomas Morin, Network Architect at France Telecom Orange

‘This is a highly recommended book for network design engineers who want to update themselves with the latest MPLS development, or those who want to learn this technology thoroughly. In addition to the impressive technology coverage and depth, the book is also a delightful reading!’

Lei Wang, Department manager Mobile IP Transport, Telenor

‘MPLS-Enabled Applications is an excellent read for network engineers involved in the design of MPLS networks and services. It can serve as an introduction to MPLS networking or as a reference book for the advanced engineer. It discusses practical issues that must be considered in the design of MPLS networks and services, including MPLS-TE, MPLS-IPVPNs and MPLS L2VPNs. It also discusses current topics that are still evolving in the industry such as inter-AS/area MPLS-TE, point-to-multipoint LSPs and IPVPN multicast, providing a good overview of the issues being addressed and the current industry direction.’

Nabil N. Bitar, Principal member of Technical Staff and lead network architect, Verizon

‘MPLS-Enabled Applications: Emerging Developments and New Technologies second edition, by Ina Minei and Julian Lucek, presents the current state-of-the-art in the specification, development, and application of MPLS and its related technologies. I believe, the readers will find the book to be a very valuable resource. I am pleased to see that the third edition of this book covers contemporary topics in the Internet industry such as MPLS-TP.’

Bijan Jabbari, PhD, Founder of Isocore, and Professor of Electrical Engineering, George Mason University

‘This is the MPLS book that I reference the most and recommend to all my colleagues. It is written in an easy-to-follow approach that starts with basic concepts and then gradually ramps to advanced topics. It is timely in its coverage of new developments such as MPLS-TP and BGP/MPLS mVPNs, yet exhaustive by addressing all aspects of MPLS including the newer advances. I have personally used this book to architect designs such as broadcast video over IP/MPLS, hierarchical video-on-demand library distribution using BGP/MPLS mVPN, and a MPLS-based network supporting triple-play services over a BGP and PIM-free Core.’

Mazen Khaddam, Principal lead network architect, network architecture group, Cox communications

‘This book is a wonderfully comprehensive overview of not just the underlying technology, but also the many use case applications of MPLS. It's a must have for networking professionals.’

Dorian Kim, Director of Network Development, NTT America

‘MPLS-Enabled Applications takes a unique and creative approach in explaining MPLS concepts and how they are applied in practice to meet the needs of Enterprise and Service Provider networks. I consistently recommend this book to colleagues in the engineering, education and business community.’

Dave Cooper, Chief IP Technologist, Global Crossing Ltd.

‘This book presents clear, comprehensive descriptions of the various scenarios in which the MPLS toolkit can be used to provide reliable and quality connectivity. It includes background information, detailed explanations on how to enable different services and applications, and precise technical and operational considerations. Business drivers for emerging technologies are discussed as well as practical and real deployment scenarios. Highlighting the hottest trends in the industry, this invaluable book describes how best to fit the pieces of the puzzle together to efficiently enable new applications and services.’

Nurit Sprecher, Senior specialist, Packet Transport Evolution, Nokia Siemens Networks

MPLS-Enabled Applications

Wiley Series in Communications Networking & Distributed Systems

Series Editors:

David Hutchison, Lancaster University, Lancaster, UK

Serge Fdida, Université Pierre et Marie Curie, Paris, France

Joe Sventek, University of Glasgow, Glasgow, UK

The ‘Wiley Series in Communications Networking & Distributed Systems’ is a series of expert-level, technically detailed books covering cutting-edge research, and brand new developments as well as tutorial-style treatments in networking, middleware and software technologies for communications and distributed systems. The books will provide timely and reliable information about the state-of-the-art to researchers, advanced students and development engineers in the Telecommunications and the Computing sectors.

Other titles in the series:

Wright: Voice over Packet Networks 0-471-49516-6 (February 2001)

Jepsen: Java for Telecommunications 0-471-49826-2 (July 2001)

Sutton: Secure Communications 0-471-49904-8 (December 2001)

Stajano: Security for Ubiquitous Computing 0-470-84493-0 (February 2002)

Martin-Flatin: Web-Based Management of IP Networks and Systems 0-471-48702-3 (September 2002)

Berman, Fox, Hey: Grid Computing. Making the Global Infrastructure a Reality 0-470-85319-0 (March 2003)

Turner, Magill, Marples: Service Provision. Technologies for Next Generation Communications 0-470-85066-3 (April 2004)

Welzl: Network Congestion Control: Managing Internet Traffic 0-470-02528-X (July 2005)

Raz, Juhola, Serrat-Fernandez, Galis: Fast and Efficient Context-Aware Services 0-470-01668-X (April 2006)

Heckmann: The Competitive Internet Service Provider 0-470-01293-5 (April 2006)

Dressler: Self-Organization in Sensor and Actor Networks 0-470-02820-3 (November 2007)

Berndt: Towards 4G Technologies: Services with Initiative 0-470-01031-2 (March 2008)

Jacquenet, Bourdon, Boucadair: Service Automation and Dynamic Provisioning Techniques in IP/MPLS Environments 0-470-01829-1 (March 2008)

Gurtov: Host Identity Protocol (HIP): Towards the Secure Mobile Internet 0-470-99790-7 (June 2008)

Boucadair: Inter-Asterisk Exchange (IAX): Deployment Scenarios in SIP-enabled Networks 0-470-77072-4 (January 2009)

Fitzek: Mobile Peer to Peer (P2P): A Tutorial Guide 0-470-69992-2 (June 2009)

Shelby: 6LoWPAN: The Wireless Embedded Internet 0-470-74799-4 (November 2009)

Stavdas: Core and Metro Networks 0-470-51274-1 (February 2010)

Gómez Herrero, van der Ven, Network Mergers and Migrations: Junos® Design and Implementation 0-470-74237-2 (March 2010)

Jacobsson, Niemegeers, Heemstra de Groot, Personal Networks: Wireless Networking for Personal Devices 0-470-68173-X (June 2010)

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Library of Congress Cataloging-in-Publication Data

Minei, Ina. MPLS-enabled applications : emerging developments and new technologies / Ina Minei, Julian Lucek. p. cm. Includes bibliographical references and index. ISBN 978-0-470-66545-9 (pbk.) 1. MPLS standard. 2. Extranets (Computer networks) I. Lucek, Julian. II. Title. TK5105.573.M56 2010 621.382'16–dc22 2010029550

A catalogue record for this book is available from the British Library.

ISBN: 9780470665459 (P/B) ePDF ISBN: 9780470976166 oBook ISBN: 9780470976173 ePub ISBN: 9780470976135

About the Authors

Ina Minei joined Juniper Networks in 2000 and is currently Director of IP and MPLS technologies. During this time she worked on the implementation of LDP and RSVP-TE, helped define new protocol extensions, and worked with numerous customers on network design. Her focus has been on next-generation network technologies, in particular MPLS protocols and applications. She previously worked at Cisco for two years in various software development projects for routers and switches. Ms Minei is an active participant in industry forums and conferences and holds several patents in the area of IP and MPLS. She earned a Master's degree in computer science from the Technion, Israel.

Julian Lucek joined Juniper Networks in 1999 and is currently a Distinguished Systems Engineer in the Europe, Middle East and Africa region, where he has been working with many service providers on the design and evolution of their networks. He previously worked at BT for several years, at first in the Photonics Research Department and later in the data transport and routing area. During this time, he gained a PhD in ultrahigh-speed data transmission and processing from Cambridge University. He is the holder of several patents in the area of communications technology. He has a Master's degree in Physics from Cambridge University and holds Juniper Networks Certified Internet Expert (JNCIE) #21.

Foreword

Yakov Rekhter, Juniper Fellow, Juniper Networks

Multi-Protocol Label Switching (MPLS) began in the mid-1990s with just two modest design objectives. The first was a better integration of ATM with IP, a goal that we hoped could be met by providing a single IP-based control plane that would span both ATM switches and IP routers. The second objective was to augment the IP control plane with some additional functionality, namely traffic engineering using constraint-based routing that was already present in the ATM control plane.

Not long after it started, MPLS usage was extended to applications such as Circuit Cross Connect (CCC), ATM and Frame Relay service over an IP/MPLS infrastructure (draft-martini), BGP/MPLS VPNs (2547 VPNs) and then Virtual Private LAN Services (VPLS). The original constraint-based routing functionality evolved beyond traffic engineering to applications such as fast reroute and Differentiated Services Traffic Engineering (DiffServ-TE).

The idea of a single control plane for both ATM switches and IP routers evolved into Generalized Multi-Protocol Label Switching (GMPLS), which provides a single control plane that could span not only routers and ATM switches but SONET/SDH and optical cross connects as well.

One of the recent MPLS developments deserving of mention here is the use of MPLS in the access network. Expanding MPLS into the access network brings with it scalability challenges. The third edition describes a solution, known as ‘Seamless MPLS’, that addresses these challenges.

Since the first edition of this book, considerable progress has been made in the area of MPLS multicast, IP multicast with BGP/MPLS VPNs, and IP multicast with VPLS. Advances in these areas were included in the second edition of this book. The third and current edition further expands upon these developments by covering such topics as supporting multicast extranets in BGP/MPLS VPNs and supporting Internet multicast over an MPLS infrastructure. This edition also presents in detail the scalability comparison between two schemes of supporting multicast in BGP/MPLS VPNs – the first one based on the PIM/GRE solution (known informally as ‘draft-rosen’), and the second based on NG multicast for L3VPN (BGP/MPLS mVPN). As an ever-increasing array of services has been developed surrounding MPLS infrastructure, the importance of high service availability and its successful provision has come to light. Since the second edition of this book, significant progress has been made in the area of scalable fast protection based on the technique of local repair; these developments and their implications are included in this edition.

One important development since the publication of the second edition of this book is MPLS Transport Profile (MPLS-TP), a technology driven by the desire of the service providers to transition their transport infrastructure from circuit-switched based technologies (SONET/SDH) to packet-based switching technology based on MPLS. This edition provides an overview of MPLS-TP, and clarifies the motivations behind and requirements for its adoption.

It is important to keep in mind that in all of the applications mentioned above, MPLS is just one of the components of such applications, albeit a critical one. If we look back at the time when MPLS was created, and compare its design objectives with what MPLS is used for today, we notice several things. First of all, most of the applications of MPLS that we have today were not conceived of during the original design of MPLS, while some of the applications conceived of during the original design of MPLS are no longer relevant. For example, the original design goal of a better integration of ATM and IP routers by having a single control plane that spans both ATM switches and routers is a thing in the past. And while the ability to offer ATM service over an IP/MPLS infrastructure is still relevant, it becomes less and less important relative to the Ethernet service over an IP/MPLS infrastructure. While originally MPLS was conceived as a technology solely for the Service Providers, we see today how MPLS is gradually penetrating the enterprise environment. Additionally, over time the whole MPLS concept evolved from Multi-Protocol Label Switching to Multi-Purpose Label Switching.

A new technology quite often generates opposition, and MPLS was by no means an exception. You may all remember how MPLS was branded by its opponents in negative terms as ‘bad’, ‘evil’, ‘a social disease’ or ‘a nightmare of unprecedented proportions’. To put this in a proper perspective, we need to keep in mind that technologies exist not for their own sake but for the purpose of solving business problems. Therefore, talking about ‘good’ technologies versus ‘bad/evil’ technologies has little practical relevance; what is of great relevance is how well a particular technology meets business needs.

One might wonder how to judge how well a particular technology, like MPLS, meets business needs. To answer this question I would like to invoke the words of Cervantes' Don Quixote: ‘the proof of the pudding is in the eating’, to which I would add: ‘and not in the debate about the pudding’. That being said, the ultimate judge of how well a particular technology meets business needs is the marketplace. It is the judgment of the marketplace that determines whether a particular technology deserves to live or to die; and with respect to MPLS the market made its verdict loud and clear – MPLS is here to stay.

Preface

In the three years since we began the previous edition of this book, so many new MPLS developments have taken place that our publisher and many readers suggested that a third edition would be useful. Two particular note-worthy developments since the second edition are Seamless MPLS – an architecture to scale networks to 100,000+ MPLS nodes – and MPLS-TP, which provides the infrastructure for MPLS-based transport networks. The motivation for the book remains the same: MPLS is moving so fast that some of its new applications have already been deployed in production networks, yet are not described anywhere in book form. In many cases, the only available resources are the IETF drafts which list the extensions needed to produce interoperable implementations. These documents often assume familiarity with the problem at hand and do not discuss why a particular solution has been chosen or explain its pros and cons. The third edition of MPLS-Enabled Applications attempts to fill this gap and provide the reader with an understanding of both the problem and why the solution looks the way it does.

Therefore, when we describe the mechanisms underpinning an MPLS application, the emphasis is on giving an overview of the protocol machinery without delving into the bits and bytes of each protocol message. This allows us to convey the concepts without making it difficult to see the wood for the trees. Also, some of the mechanisms that we write about are currently being defined, so details of the protocol messages may change, but the concepts are less likely to. References at the end of each chapter point to the documents describing the message formats and processing rules. Because a lot of the content in this book deals with technologies that are still, literally, works in progress, several things may happen. Firstly, some proposals may be abandoned or fail to become widely adopted. Secondly, different vendors may introduce the technology at different times, and finally, the solution may evolve and change as implementation and deployment experience is gained. Therefore, the fact that we discuss a particular technology in this book does not guarantee that it is available or deployed.

Although we both happen to work for the same router vendor, the book is not vendor-specific. Occasionally, we point out some vendor-specific quirks if they are relevant to the discussion, or aid in understanding a particular topic. Many of the topics discussed are still under debate in the IETF, and naturally our personal views on one topic or another may be stated more strongly than the opposing view.

WHO SHOULD READ THIS BOOK?

The intended audience of this book includes employees of network operators and network equipment vendors, customers of service providers who are interested in the mechanisms underpinning the services that they buy, network professionals who want to keep up to date with the latest advances in MPLS and students of network technology. To make this book more accessible to both the student and to the practitioner of MPLS, we have added study questions at the end of each chapter.

We assume that the reader has some degree of familiarity with network technology and routing protocols, in particular BGP and the link-state IGPs, but these are not a requirement to benefit from the book. Although our main aim is to cover the cutting-edge developments of MPLS, the Foundation chapter allows the reader unfamiliar with MPLS to get up to speed in order to benefit from the remainder of the book. Even when discussing basic topics such as traffic engineering or fast reroute, we also explore the more interesting and advanced aspects of the technology.

WHAT IS NEW IN THE THIRD EDITION?

In this third edition, we aim to capture the latest developments in the field. For this reason, we added three new chapters. Chapter 11 covers advanced topics in multicast in L3VPNs, focusing on new developments in the BGP/MPLS scheme, which has gained significant deployment over the last few years. Chapter 14 discusses advanced protection schemes for the LSP tail-end, thus enabling sub 50 ms end-to-end service restoration. Finally, Chapter 17 provides an overview of MPLS-TP, the transport profile for MPLS, which will form the foundation for packet-switched transport networks. Additional material was added and updated throughout the book. Chapter 16, covering MPLS in access networks, has new sections describing the Seamless MPLS architecture, including the solutions for both unicast and multicast. The book also has new material covering the Live-live and Live-standby schemes for multicast resilience, point to multipoint pseudowires, pseudowire redundancy and VPLS Interprovider Option E. The study questions at the end of each chapter are intended to help readers test their understanding of the topics discussed and can serve to trigger debate on the pros and cons of a particular technology to a particular deployment.

HOW THIS BOOK IS ORGANIZED

The book is divided into three parts, each containing several chapters. Part One describes the MPLS infrastructure tools used as the foundation to build services, Part Two covers the MPLS-based services and Part Three explores advanced topics.

The structure of Part One

Chapter 1, the Foundations chapter, reviews the control plane and forwarding plane mechanisms associated with MPLS. In this chapter, we give an overview of the LDP and RSVP signaling protocols and compare the two.

Chapter 2 discusses MPLS Traffic Engineering, which gives service providers control over the path taken by traffic through their network and the ability to give bandwidth guarantees. In this context, we look at the impact of TE on network scalability, as well as at solutions for TE in LDP networks.

Chapter 3 explores the topic of Protection and Restoration in MPLS networks, essential to allowing MPLS networks to carry mission-critical traffic. We cover link and node protection, their respective scaling properties and the cost of bandwidth protection. We also explore more advanced topics such as fate sharing and the new developments for providing fast restoration in IP and LDP networks.

Chapter 4 presents Differentiated Services (DiffServ) Aware Traffic Engineering, which allows traffic engineering to be applied with per-class granularity, bringing QoS to the network.

Chapter 5 introduces Interdomain Traffic Engineering. Both the signaling and computation aspects are discussed, and path-computation elements are also reviewed.

Chapter 6 is devoted to MPLS multicast functionality. This chapter covers not just P2MP LSP setup with RSVP and LDP but also advanced topics such as upstream label allocation and hierarchies of P2MP LSPs. MPLS multicast is currently of great interest as it allows MPLS to be used in broadcast TV and IPTV applications and because it is an essential part of the next-generation L3VPN multicast solutions discussed in Part Two.

The structure of Part Two

Chapters 7, 8, 9, 10 and 11 are devoted to Layer 3 VPNs – the most widespread application of MPLS to date. Chapters 7 through 9 focus on unicast traffic in VPNs. Chapter 7 provides a tutorial on L3VPN and explains the basic concepts, Chapter 8 discusses more advanced topics such as route target filtering and scalability analysis, and Chapter 9 covers hierarchical VPNs. Chapters 10 and 11 dive into the topic of multicast VPNs. Chapter 10 presents and compares the PIM/GRE and the BGP/MPLS solutions for multicast VPNs, while Chapter 11 focuses entirely on advanced topics such as extranet and inter-AS support in the BGP/MPLS solution, which has gained a lot of traction in the last few years.

Chapter 12 describes the rapidly growing area of Layer 2 transport over MPLS, including pseudowires and Layer 2 VPNs. These allow service providers to migrate ATM and Frame Relay services to an IP/MPLS network and to offer Ethernet-based alternatives to those services.

Chapter 13 describes the Virtual Private LAN Service (VPLS). This allows a service provider to offer a very simple-to-use service to enterprise customers, in which the customer's sites appear to be attached to the same LAN. Multicast support over VPLS, an area which has seen a lot of change in recent years, is also discussed.

The structure of Part Three

Chapter 14 describes advances in protection schemes aimed at providing 50 ms recovery times for end-to-end services. As we show in the chapter, a critical building block is providing protection of the LSP tail end.

Chapter 15 covers some aspects of the management and troubleshooting of MPLS networks. The subject of management of MPLS networks could fill an entire book by itself and a single chapter does not do it justice. However, we attempt to show some of the challenges (such as ICMP tunneling) and some of the available tools, such as LSPing.

Chapter 16 provides an overview of the emerging trend of using MPLS in the access network, explains why this technology is taking off and describes the various deployment models, as well as describing the new and increasingly popular Seamless MPLS architecture.

Chapter 17 discusses the much-debated topic of MPLS-TP, the transport profile for MPLS. MPLS-TP is currently the most active standardization area in MPLS. In order to track developments in this field, it is important to understand both the technology itself and what drives the industry to rally behind it in this way.

The final chapter takes a look at the achievements of MPLS to date and how MPLS may in future extend to DCNs, mobile Radio Access Networks and enterprise networks.

Appendix contains details of how xDSL architectures can be mapped onto an MPLS-based access network.

REFERENCES

At the end of each chapter, there is a list of references. In the body of the text, these references appear in brackets, like this [REF1]. Many of the references are IETF documents. As these documents progress in the IETF process, their revision number and document name may change. Therefore, when looking up a reference online, search by the author and title rather than by the document name.

In some chapters, we have included a section with further reading. These are documents that we thought would be useful for those wanting to broaden their knowledge on a particular topic.

Ina Minei, Sunnyvale, CAJulian Lucek, Ipswich, UK

Acknowledgements

This book would not have existed if it were not for the following three people: Yakov Rekhter, Aviva Garrett and Patrick Ames, and to them we extend our most heartfelt thanks.

Yakov Rekhter encouraged us to pursue this project and provided valuable insight throughout the writing process, from the book proposal, in-depth discussions of many topics, in particular cutting edge topics such as multicast support in L3VPNs, seamless MPLS and advanced protection schemes and finally detailed technical reviews of numerous chapters. Most importantly, his faith in our ability to do this work was one of the main factors that determined us to go ahead with this project.

Aviva Garrett was the first person to hear about this idea, encouraged it and arranged all the required support within Juniper Networks, as well as providing detailed editorial review, sometimes on extremely short notice.

Patrick Ames guided us through the intricate process of bringing a book from proposal to the printing press and provided moral support and appropriate scolding as necessary. We would not have been able to pull this off without him. Patrick also did all the hard work of preparing the manuscript (and in particular the art manuscript) for editing.

All three editions of this book benefited from the contribution of many people. We would like to thank our following colleagues:

Pedro Marques, for his thorough review of almost all chapters, for many technical discussions and for contributing the analysis of VPN scaling and RR scaling.

Arthi Ayyangar, for her insight on all topics RSVP and TE-related, for many technical discussions throughout our years of working together and for the careful review of numerous chapters.

Steven Lin, for reading and commenting on the entire manuscript of the first edition, on a very tight schedule.

Der-Hwa Gan, for his mentoring role on TE, RSVP and MPLS, and for his very thorough technical review and comments.

Chaitanya Kodeboyina (CK), for very detailed reviews and discussions on several chapters.

Josef Buchsteiner, for always bringing up tough customer problems and for the timely reviews of selected chapters.

Serpil Bayraktar, for never leaving open ends and for very careful reading of the VPN and interdomain TE chapters.

Amir Tabdili, for always asking the hard questions and for reviewing selected chapters.

Quaizar Vohra, for his insight into Layer 2 circuits and the IGP, and for his technical review of these topics.

Margarida Correia, for always questioning proposed solutions to customer problems, and for technical review of selected chapters.

Hector Avalos, for valuable technical discussions and technical review of selected chapters.

Nischal Sheth, for being a mentor on LDP and for numerous discussions on all topics MPLS-related, as well as for a thorough review of the Advanced Protection chapter, where he provided valuable insights.

Kireeti Kompella, for many technical discussions, for his insight into all aspects of the MPLS technology and for his review of the MPLS in Access Networks chapter. The discussion of ‘Option 1’ and ‘Option 2’ deployment models for MPLS within that chapter is largely based on Kireeti's analysis of this topic.

Hannes Gredler, for his review of the Protection and Restoration and the Advanced Protection chapters and numerous discussions on tailend protection.

Nitin Bahadur, for his review of the Management, Protection and Restoration, Multicast over MPLS and MPLS-TP chapters.

Amit Shukla, for a detailed review of the VPLS chapter and valuable insights in the LDP/BGP VPLS interworking scheme described there.

Derek Harkness, for his expertise on broadband DSL architectures and his review of the MPLS in Access Networks chapter.

Nils Swart, for his expertise on Metro Ethernet and his review of the MPLS in Access Networks chapter.

João Gomes, for his expertise on mobile networks and his review of the Conclusions chapter.

Pierre Bichon, for his expertise on mobile networks and his review of the Conclusions chapter.

Senad Palislamovic, for his thorough review of all the study questions and their answers for the second edition of the book.

Dave Ward, for his detailed review of the MPLS-TP chapter, and for his perspective on the technology, provided both through the presentations referenced in the chapter and through the review.

John Drake, for his thorough review of the MPLS-TP chapter, and his insight into the technology, which at the time of the writing was still very much work in progress.

Nurit Sprecher for her suggestions for additional topics to cover in MPLS-TP and comments on the MPLS-TP material.

Kurt Windisch, for his detailed and timely review of advanced topics in multicast in VPNs. Kevin Wang, for his comments on the Advanced Protection chapter, for which he provided valuable implementation perspective.

Manish Gupta, for his comments on selected topics in VPLS and L2VPN.

As always, any errors and omissions are the responsibility of the authors.

We would also like to acknowledge the support and assistance of Juniper Networks for providing the necessary resources to work on the third edition of the book.

Last but not least we would like to thank the wonderful team at Wiley: Tiina Ruonamaa, Sarah Tilley, Anna Smart, and Jasmine Chang for their support and guidance.

Finally, the authors would like to express their personal thanks to family and friends:

Ina Minei – First of all, I would like to thank my husband Pedro Marques for being my strongest supporter and harshest critic, for having infinite patience throughout the entire project, not once, not twice, but three times around. I would not have been able to do this without his support. Second, I would like to thank my father for the long hours he spent with me in my high school years, teaching me English and writing.

Julian Lucek – I would like to thank my partner Rachel and our daughters Emma and Hannah for their great patience and support during the writing of both editions of this book. Also I would like to thank my parents for their encouragement and for looking after my daughters during my writing sessions.

Part One

1

Foundations

1.1 HISTORICAL PERSPECTIVE

In only a few years, Multi-Protocol Label Switching (MPLS) has evolved from an exotic technology to a mainstream tool used by service providers to create revenue-generating services. There is rapid deployment of MPLS-enabled services and active development of new mechanisms and applications for MPLS in the standards bodies. This book aims to describe the fundamental mechanisms used by MPLS and the main service types that MPLS enables, such as Virtual Private Networks (VPNs). We include descriptions of new applications of MPLS that are currently under development.

The history of MPLS and its precursors is described in [Davie Rekhter] and [Doyle Kolon]. The first Internet Engineering Task Force (IETF) MPLS Working Group Meeting took place in April 1997. That working group still exists, and MPLS has grown to the extent that it underpins much of the activity of several other working groups in the IETF, such as Layer 3 VPN (l3vpn), Layer 2 VPN (l2vpn), Pseudo Wire Emulation Edge-to-Edge (pwe3) and Common Control and Measurement Plane (ccamp). Part of the original MPLS problem statement [MPLS97] from the first MPLS working group meeting is shown below. It contains four items that the group aimed to address through the development of MPLS. It is interesting to examine these to see which items are still relevant today: