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‘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 stan-
dards, 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: Emerging Developments and New Technologies Third Edition
Ina Minei and Julian Lucek © 2011 John Wiley & Sons, Ltd
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‘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 edi-
tion, 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 technol-
ogy, 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 con-
cepts 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
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MPLS-Enabled Applications
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WILEY SERIES IN COMMUNICATIONS NETWORKING
& DISTRIBUTED SYSTEMS
Series Editors:
David Hutchison, Lancaster University, Lancaster, UK
Serge Fdida, Universit´e 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 network-
ing, 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 Commu-
nications 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 Tech-
niques 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 Net-
works 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)
G´omez Herrero, van der Ven, Network Mergers and Migrations: Junos R⃝ 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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MPLS-Enabled Applications
Emerging Developments
and New Technologies
Third Edition
Ina Minei
Juniper Networks
Julian Lucek
Juniper Networks
John Wiley & Sons, Ltd
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This edition first published 2011
C⃝ 2011 John Wiley & Sons, Ltd.
Registered office
John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ,
United Kingdom
For details of our global editorial offices, for customer services and for information about
how to apply for permission to reuse the copyright material in this book please see our
website at www.wiley.com.
The right of the author to be identified as the author of this work has been asserted in
accordance with the Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act
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covered. It is sold on the understanding that the publisher is not engaged in rendering
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services of a competent professional should be sought.
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
Set in 10/12pt Palatino by Aptara Inc., New Delhi, India.
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Contents
About the Authors
xix
Foreword
xxi
Preface
xxv
Acknowledgements
xxxi
Part One
1 Foundations
3
1.1 Historical perspective
3
1.2 Current trends
5
1.3 MPLS mechanisms
6
1.3.1 Forwarding plane mechanisms
7
1.3.2 Control plane mechanisms
11
1.3.3 Transport of IPv6 over an IPv4 MPLS core
32
1.4 Conclusion
35
1.5 References
35
1.6 Further reading
36
1.7 Study questions
36
2 Traffic Engineering with MPLS (MPLS-TE)
39
2.1 Introduction
39
2.2 The business drivers
39
2.3 Application scenarios
40
2.4 Setting up traffic-engineered paths using MPLS-TE
43
2.4.1 LSP priorities and preemption
43
2.4.2 Information distribution – IGP extensions
44
2.4.3 Path calculation – CSPF
46
2.4.4 Path setup – RSVP extensions and admission control
49
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CONTENTS
2.5
Using the traffic-engineered paths
51
2.6
Deployment considerations
54
2.6.1 Scalability
54
2.6.2 Reservation granularity
56
2.6.3 Routing challenges
57
2.7
Using traffic engineering to achieve resource
optimization
57
2.7.1 Autobandwidth – dealing with unknown
bandwidth requirements
58
2.7.2 Sharing links between RSVP and other traffic –
dealing with unknown bandwidth availability
59
2.7.3 Other methods for optimization of
transmission resources in MPLS networks
60
2.8
Offline path computation
61
2.9
Conclusion
64
2.10 References
65
2.11 Further reading
65
2.12 Study questions
65
3 Protection and Restoration in MPLS Networks
67
3.1
Introduction
67
3.2
The business drivers
68
3.3
Failure detection
69
3.4
End-to-end protection
70
3.4.1 Control over the traffic flow following a failure
71
3.4.2 Requirement for path diversity
71
3.4.3 Double-booking of resources
72
3.4.4 Unnecessary protection
72
3.4.5 Nondeterministic switchover delay
72
3.5
Local protection using fast reroute
73
3.5.1 Case (i): link protection, for the facility
protection case
75
3.5.2 Case (ii): link protection, for the 1:1 protection case
77
3.5.3 Case (iii): node protection, for the facility
protection case
78
3.5.4 Case (iv): node protection, for the 1:1 protection case
79
3.6
Link protection
81
3.6.1 What happens before the failure
82
3.6.2 What happens after the failure
87
3.7
Node protection
89
3.8
Additional constraints for the computation of the
protection path
91
3.8.1 Fate sharing
91
3.8.2 Bandwidth protection
93
3.8.3 Bandwidth protection and DiffServ
96
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ix
3.9
Interaction of end-to-end protection and fast reroute
97
3.10 Deployment considerations for local protection
mechanisms
98
3.10.1 Scalability considerations
98
3.10.2 Evaluating a local protection implementation
101
3.10.3 The cost of bandwidth protection
103
3.11 IP and LDP FRR
105
3.11.1 The tunnel-based approach
107
3.11.2 The alternate-path approach
108
3.12 Conclusion
110
3.13 References
111
3.14 Further reading
111
3.15 Study questions
111
4 MPLS DiffServ-TE
113
4.1
Introduction
113
4.2
The business drivers
114
4.3
Application scenarios
115
4.3.1 Limiting the proportion of traffic from a
particular class on a link
115
4.3.2 Maintaining relative proportions of traffic on links
117
4.3.3 Providing guaranteed bandwidth services
117
4.4
The DiffServ-TE solution
117
4.4.1 Class types
117
4.4.2 Path computation
118
4.4.3 Path signaling
121
4.4.4 Bandwidth constraint models
122
4.4.5 Overbooking
127
4.4.6 The DiffServ in DiffServ-TE
129
4.4.7 Protection
130
4.4.8 Tools for keeping traffic within its reservation limits
131
4.4.9 Deploying the DiffServ-TE solution
132
4.5
Extending the DiffServ-TE solution with
multiclass LSPs
133
4.6
Conclusion
134
4.7
References
134
4.8
Further reading
135
4.9
Study questions
135
5 Interdomain Traffic Engineering
137
5.1
Introduction
137
5.2
The business drivers
137
5.3
Setting up interdomain TE LSPs
139
5.3.1 Path setup
140
5.3.2 Path computation
144
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5.3.3 Reoptimization
154
5.3.4 Protection and fast reroute
155
5.4
Interprovider challenges
157
5.5
Comparison of the LSP setup methods
158
5.6
Conclusion
159
5.7
References
160
5.8
Further reading
161
5.9
Study questions
161
6 MPLS Multicast
163
6.1
Introduction
163
6.2
The business drivers
164
6.3
P2MP LSP mechanisms
165
6.3.1 Forwarding plane mechanisms
165
6.3.2 Control plane mechanisms
167
6.4
LAN procedures for P2MP LSPs
176
6.4.1 Upstream label allocation
177
6.5
Coupling traffic into a P2MP LSP
178
6.5.1 Coupling Layer 2 traffic into a P2MP LSP
179
6.5.2 Coupling IP unicast traffic into a P2MP LSP
179
6.5.3 Coupling IP multicast traffic into a P2MP LSP
180
6.6
MPLS fast reroute
181
6.7
Ingress redundancy for P2MP LSPs
183
6.8
P2MP LSP hierarchy
184
6.8.1 P2MP LSP hierarchy forwarding plane operation
186
6.8.2 P2MP LSP hierarchy control plane operation
187
6.9
Applications of point-to-multipoint LSPs
187
6.9.1 Application of P2MP TE to broadcast TV distribution
188
6.9.2 Application of P2MP LSPs to L3VPN multicast
191
6.9.3 Application of P2MP LSPs to VPLS
193
6.10 Conclusion
193
6.11 References
193
6.12 Study questions
195
Part Two
7 Foundations of Layer 3 BGP/MPLS Virtual Private Networks
199
7.1
Introduction
199
7.2
The business drivers
200
7.3
The overlay VPN model
201
7.4
The peer VPN model
202
7.5
Building the BGP/MPLS VPN solution
205
7.5.1 VPN routing and forwarding tables (VRFs)
205
7.5.2 Constrained route distribution
207
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xi
7.5.3 VPN-IPv4 addresses and the route
distinguisher (RD)
208
7.5.4 The route target (RT)
209
7.5.5 The solution so far – what is missing?
215
7.5.6 VPN label
216
7.6
Benefits of the BGP/MPLS VPN solution
221
7.7
References
222
7.8
Further reading
222
7.9
Study questions
223
8 Advanced Topics in Layer 3 BGP/MPLS Virtual
Private Networks
225
8.1
Introduction
225
8.2
Routing between CE and PE
225
8.3
Differentiated VPN treatment in the core
230
8.4
Route reflectors and VPNs
231
8.5
Scalability discussion
235
8.5.1 Potential scaling bottlenecks
236
8.5.2 The cost of growing the VPN network
238
8.6
Convergence times in a VPN network
243
8.6.1 Convergence time for a customer route change
243
8.6.2 Convergence time for a failure in the
provider’s network
244
8.7
Security issues
244
8.7.1 Can traffic from one VPN ‘cross over’ into
another VPN?
245
8.7.2 Can a security attack on one VPN affect
another VPN?
245
8.7.3 Can a security attack against the service
provider’s infrastructure affect the
VPN service?
246
8.8
QoS in a VPN scenario
246
8.9
IPv6 VPNs
248
8.10 Conclusion
251
8.11 References
251
8.12 Further reading
252
8.13 Study questions
252
9 Hierarchical and Inter-AS VPNs
255
9.1
Introduction
255
9.2
Carriers’ carrier – service providers as VPN customers
256
9.2.1 ISP as a VPN customer
257
9.2.2 VPN service provider as a VPN customer –
hierarchical VPN
262
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CONTENTS
9.3
Multi-AS backbones
266
9.3.1 Option A: VRF-to-VRF connections at the ASBR
266
9.3.2 Option B: EBGP redistribution of labeled
VPN-IPv4 routes
268
9.3.3 Option C: multihop EBGP redistribution of
labeled VPN-IPv4 routes between the source
and destination AS, with EBGP redistribution
of labeled IPv4 routes from one AS to the
neighboring AS
269
9.4
Interprovider QoS
271
9.5
Conclusion
272
9.6
References
272
9.7
Further reading
273
9.8
Study questions
273
10 Multicast in a Layer 3 VPN
275
10.1 Introduction
275
10.2 The business drivers
276
10.3 mVPN – problem decomposition
278
10.4 The original multicast solution− PIM/GRE mVPN
(draft-rosen)
279
10.4.1 PIM/GRE mVPN – routing information
distribution using PIM C-instances
280
10.4.2 PIM/GRE mVPN – carrying multicast traffic
across the core using multicast distribution trees
281
10.4.3 Properties of the PIM/GRE mVPN solution
283
10.5 NG multicast for L3VPN – BGP/MPLS mVPN
(NG mVPN)
286
10.5.1 Requirements for support of PIM-SM SSM in
an mVPN
286
10.5.2 BGP/MPLS mVPN – carrying multicast
mVPN routing information using C-multicast routes
287
10.5.3 BGP/MPLS mVPN – carrying traffic across
the provider network using inter-PE MPLS tunnels
292
10.5.4 BGP/MPLS mVPN – inter-PE tunnels –
inclusive and selective tunnels
292
10.5.5 BGP/MPLS mVPN – carrying traffic from
several mVPNs onto the same inter-PE tunnel
294
10.5.6 BGP/MPLS mVPN – creating inter-PE
tunnels using BGP autodiscovery routes
295
10.5.7 Requirements for support of PIM ASM in
an mVPN
299
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xiii
10.5.8 BGP/MPLS mVPN – carrying mVPN active
source information using BGP source active
autodiscovery routes
300
10.6 Comparison of PIM/GRE and BGP/MPLS mVPNs
303
10.6.1 VPN model used
303
10.6.2 Protocol used in the control plane
304
10.6.3 Data-plane mechanisms
305
10.6.4 Service provider network as a ‘LAN’
306
10.6.5 Deployment considerations
306
10.7
Conclusion
307
10.8
References
307
10.9
Further reading
308
10.10 Study questions
309
11 Advanced Topics in BGP/MPLS mVPNs
311
11.1
Introduction
311
11.2
BGP/MPLS mVPN – inter-AS operations
311
11.3
Support of PIM DM in BGP/MPLS mVPN
316
11.4
Discovering the RP – auto-RP and BSR support in
BGP/MPLS mVPN
317
11.5
Implementing extranets in BGP/MPLS mVPN
319
11.6
Transition from draft-rosen to BGP/MPLS mVPNs
322
11.7
Scalability discussion
325
11.7.1 PIM/GRE mVPN control plane scaling
325
11.7.2 BGP/MPLS mVPN control plane scaling
326
11.8
Achieving multicast high availability with
BGP/MPLS mVPN
328
11.8.1 Live-Standby multicast delivery using
BGP/MPLS mVPN
329
11.8.2 Live-Live multicast delivery using
BGP/MPLS mVPN
332
11.8.3 Comparison of the Live-Live and
Live-Standby multicast high-availability schemes
335
11.9
Internet multicast service using the BGP/MPLS
mVPN technology
335
11.10 Conclusion
337
11.11 References
338
11.12 Study questions
338
12 Layer 2 Transport over MPLS
341
12.1
Introduction
341
12.2
The business drivers
341
12.3
Comparison of layer 2 VPNs and layer 3 VPNs
344
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12.4
Principles of layer 2 transport over MPLS
345
12.5
Forwarding plane
347
12.5.1 ATM cell
349
12.5.2 ATM AAL5
349
12.5.3 Frame relay
350
12.5.4 Ethernet
350
12.6
Control plane operation
351
12.6.1 Original LDP signaling scheme
351
12.6.2 BGP-based signaling and autodiscovery scheme
353
12.6.3 LDP signaling with BGP autodiscovery
357
12.6.4 Comparison of BGP and LDP approaches to
Layer 2 transport over MPLS
358
12.7
Admission control of layer 2 connections into
network
360
12.8
Failure notification mechanisms
361
12.9
Multi-homing
362
12.9.1 BGP case
362
12.9.2 LDP case
364
12.10 Layer 2 interworking
365
12.11 Circuit cross connect (CCC)
365
12.12 Point-to-multipoint Layer 2 transport
366
12.12.1 Point-to-multipoint CCC
367
12.12.2 Layer 2 Multicast VPNs
367
12.13 Other applications of Layer 2 transport
368
12.14 Conclusion
370
12.15 References
370
12.16 Study questions
371
13 Virtual Private LAN Service
373
13.1
Introduction
373
13.2
The business drivers
373
13.3
VPLS mechanism overview
375
13.4
Forwarding plane mechanisms
379
13.4.1 Forwarding of unicast frames
379
13.4.2 Broadcast and multicast frames
382
13.5
Control plane mechanisms
384
13.5.1 LDP-based signaling
384
13.5.2 BGP signaling and autodiscovery
389
13.5.3 Comparison of LDP and BGP for VPLS
control plane implementation
396
13.5.4 IGMP and PIM snooping
399
13.5.5 Use of multicast trees in VPLS
401
13.6
LDP and BGP interworking for VPLS
406
13.7
Interprovider Option E for VPLS
413
13.7.1 Comparison of interprovider schemes for VPLS
415
