Print this page Share

QOS-Enabled Networks: Tools and Foundations, 2nd Edition

ISBN: 978-1-119-10910-5
254 pages
February 2016
QOS-Enabled Networks: Tools and Foundations, 2nd Edition (1119109108) cover image


Written by two experts in the field who deal with QOS predicaments every day and now in this 2nd edition give special attention to the realm of Data Centers, QoS Enabled Networks:Tools and Foundations, 2nd Edition provides a lucid understanding of modern QOS theory mechanisms in packet networks and how to apply them in practice. This book is focuses on the tools and foundations of QoS providing the knowledge to understand what benefits QOS offers and what can be built on top of it.

See More

Table of Contents

About the Authors x

Foreword xi

Preface xiii

Acknowledgments xv

Abbreviations xvi


1 The QOS World 3

1.1 Operation and Signaling 4

1.2 Standards and Per ]Hop Behavior 5

1.3 Traffic Characterization 8

1.4 A Router without QOS 11

1.5 Conclusion 12

References 12

Further Reading 12

2 The QOS Tools 13

2.1 Classifiers and Classes of Service 13

2.2 Metering and Coloring—CIR/PIR Model 15

2.3 The Policer Tool 16

2.4 The Shaper Function 17

2.5 Comparing Policing and Shaping 18

2.6 Queue 19

2.7 The Scheduler 21

2.8 The Rewrite Tool 21

2.9 Example of Combining Tools 23

2.10 Delay and Jitter Insertion 27

2.11 Packet Loss 31

2.12 Conclusion 32

Reference 33

3 Challenges 34

3.1 Defining the Classes of Service 35

3.2 Classes of Service and Queues Mapping 37

3.3 Inherent Delay Factors 40

3.4 Congestion Points 46

3.5 Trust Borders 49

3.6 Granularity Levels 51

3.7 Control Traffic 53

3.8 Trust, Granularity, and Control Traffic 54

3.9 Conclusion 56

Further Reading 56

4 Special Traffic Types and Networks 57

4.1 Layer 4 Transport Protocols: UDP and TCP 58

4.1.1 The TCP Session 61

4.1.2 TCP Congestion Mechanism 64

4.1.3 TCP Congestion Scenario 65

4.1.4 TCP and QOS 66

4.2 Data Center 67

4.2.1 SAN Traffic 68

4.2.2 Lossless Ethernet Networks 69

4.2.3 Virtualization 71

4.2.4 Software Defined Networks 73

4.2.5 DC and QOS 74

4.3 Real ]Time Traffic 74

4.3.1 Control and Data Traffic 75

4.3.2 Voice over IP 76

4.3.3 IPTV 78

4.3.4 QOS and Real ]Time Traffic 79

Reference 80

Further Reading 80

Part II TOOLS 81

5 Classifiers 83

5.1 Packet QOS Markings 84

5.2 Inbound Interface Information 85

5.3 Deep Packet Inspection 87

5.4 Selecting Classifiers 88

5.5 The QOS Network Perspective 89

5.6 MPLS DiffServ ]TE 92

5.7 Mixing Different QOS Realms 94

5.8 Conclusion 99

References 100

6 Policing and Shaping 101

6.1 Token Buckets 101

6.2 Traffic Bursts 106

6.3 Dual ]Rate Token Buckets 109

6.4 Shapers and Leaky Buckets 110

6.5 Excess Traffic and Oversubscription 112

6.6 Comparing and Applying Policer and Shaper Tools 113

6.7 Conclusion 116

Reference 116

7 Queuing and Scheduling 117

7.1 Queuing and Scheduling Concepts 117

7.2 Packets and Cellification 119

7.3 Different Types of Queuing Disciplines 121

7.4 FIFO 121

7.5 FQ 123

7.6 PQ 125

7.7 WFQ 127

7.8 WRR 128

7.9 DWRR 131

7.10 PB ]DWRR 137

7.11 Conclusions about the Best Queuing Discipline 141

Further Reading 142

8 Advanced Queuing Topics 143

8.1 Hierarchical Scheduling 143

8.2 Queue Lengths and Buffer Size 146

8.3 Dynamically Sized versus Fixed ]Size Queue Buffers 149

8.4 RED 150

8.5 Using RED with TCP Sessions 152

8.6 Differentiating Traffic inside a Queue with WRED 154

8.7 Head versus Tail RED 156

8.8 Segmented and Interpolated RED Profiles 158

8.9 Conclusion 160

Reference 161

Further Reading 161


9 The VPLS Case Study 165

9.1 High ]Level Case Study Overview 166

9.2 Virtual Private Networks 167

9.3 Service Overview 168

9.4 Service Technical Implementation 170

9.5 Network Internals 171

9.6 Classes of Service and Queue Mapping 172

9.7 Classification and Trust Borders 174

9.8 Admission Control 175

9.9 Rewrite Rules 176

9.10 Absorbing Traffic Bursts at the Egress 179

9.11 Queues and Scheduling at Core ]Facing Interfaces 179

9.12 Queues and Scheduling at Customer ]Facing Interfaces 182

9.13 Tracing a Packet through the Network 183

9.14 Adding More Services 186

9.15 Multicast Traffic 188

9.16 Using Bandwidth Reservations 190

9.17 Conclusion 191

Further Reading 191

10 Case Study QOS in the Data Center 192

10.1 The New Traffic Model for Modern Data Centers 192

10.2 The Industry Consensus about Data Center Design 196

10.3 What Causes Congestion in the Data Center? 199

10.3.1 Oversubscription versus Microbursts 199

10.3.2 TCP Incast Problem 202

10.4 Conclusions 205

Further Reading 207

11 Case Study IP RAN and Mobile Backhaul QOS 208

11.1 Evolution from 2G to 4G 208

11.2 2G Network Components 209

11.3 Traffic on 2G Networks 211

11.4 3G Network Components 211

11.5 Traffic on 3G Networks 215

11.6 LTE Network Components 216

11.7 LTE Traffic Types 219

11.8 LTE Traffic Classes 220

11.9 Conclusion 224

References 227

Further Reading 227

12 Conclusion 228

Index 230

See More

Author Information

Miguel Barreiros is the Data Center Practice Lead at Juniper Networks responsible for the EMEA region. Previously he was a Senior Solutions Consultant focused on both Data Centers and IP/MPLS networks Since he joined Juniper Networks in 2006 he has been focused in the creation and development of solutions, and involved in projects that span all stages of building and expanding networks, from design and testing through implementation and ongoing maintenance. He began his networking career in 2000, when as a hobby he was network administrator for a British multiplayer gaming website that hosted network servers for various video games. Miguel has a B.Sc. degree in Electronics and Computer Engineering from Instituto Superior Técnico. He holds Juniper Networks Certificate Internet Expert (JNCIE) 193 and is a Juniper Networks Certified Instructor.

Peter Lundqvist, Systems Engineer, Arista Networks, Sweden
Peter Lundqvist works in system engineering at Arista Networks since May 2014. Prior to this, he was a senior Beta Engineer at Juniper Networks, supporting the field test and rollout of new features and solutions before they are public available. He has been responsible for the testing of several of the newly deployed QOS features.  Before working in the Engineering department, Peter worked as professional services engineer, in network design and implementation of large-scale networks, several of them including QOS features. Peter worked for more than 13 years at Juniper Networks, prior to which he worked in Cisco Systems as Consulting Engineer.

See More


“My long-time friends Miguel Barreiros and Peter Lundqvist have deep experience designing modern QoS strategies, and they share that experience in this book, from modern QoS building blocks to applied case studies. They’ll equip you well for designing the best QoS approach for your own network.”

Jeff Doyle


"An excellent overview of the fundamentals of QoS tools and their application, "QoS-enabled Networks" can serve both as an introduction and as a reference.  Free from vendor-specific implementation details and configuration knobs, the book focuses on core concepts and on how to apply them to real-world scenarios, making this complex topic come into sharp focus"

Ina Minei, Network Architect, Google


"This book addresses the real world scenarios faced by many telcos across the globe. Prioritisation and scheduling at the forefront of network design is key to every telco’s utopia of a fully converged, multiservice network. A great resource in the designers tool kit"

Phill Magill, Head of Network Innovation at Talk Talk Group


"This is the first book about QOS that I actually enjoyed reading precisely because the authors focused on real-life QoS and not in academic discussions about it."

Per Nihlen, IP Network Manager, NORDUnet


" This book  provides a new approach of the complex realm which is the QoS . It offers a detailed theoretical explanation of QoS mechanisms but alsogreat case studies of concrete QoS applications. This book allowed me to better grasp complex QoS configurations such as the hierarchical CoS in BNG environment. "

David Roy, IP/MPLS NOC engineer - Orange France


"This book contains useful scenarios and real world case studies which expertly convert theoretical knowledge in practical application"

Matheu Leonards, Head of Architecture, Finance and Risk, Thomson Reuters


“Mercifully, this book is not a dry academic dissertation on QoS. Rather, it offers an accessibly written and useful insight into the concepts and mechanisms of QoS that augment the tool kit of today’s Network Engineer"

Russell Thompson, Network Engineer, Telstra



See More