IP Telephony Interconnection Reference: Challenges, Models, and Engineering

360 Pages·2011·27.574 MB·English

by  Mohamed Boucadair, Isabel Borges, Pedro Miguel Neves, Olafur Pall Einarsson

IP Telephony
Interconnection
Reference
Challenges, Models, and Engineering

IP Telephony
Interconnection
Reference
Challenges, Models, and Engineering
Mohamed Boucadair s Isabel Borges
Pedro Miguel Neves s Ólafur Páll Einarsson
CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742
© 2012 by Taylor & Francis Group, LLC
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
Version Date: 2011928
International Standard Book Number-13: 978-1-4398-5179-1 (eBook - PDF)
This book contains information obtained from authentic and highly regarded sources. Reasonable efforts
have been made to publish reliable data and information, but the author and publisher cannot assume
responsibility for the validity of all materials or the consequences of their use. The authors and publishers
have attempted to trace the copyright holders of all material reproduced in this publication and apologize to
copyright holders if permission to publish in this form has not been obtained. If any copyright material has
not been acknowledged please write and let us know so we may rectify in any future reprint.
Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmit-
ted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented,
including photocopying, microfilming, and recording, or in any information storage or retrieval system,
without written permission from the publishers.
For permission to photocopy or use material electronically from this work, please access www.copyright.
com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood
Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and
registration for a variety of users. For organizations that have been granted a photocopy license by the CCC,
a separate system of payment has been arranged.
Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used
only for identification and explanation without intent to infringe.
Visit the Taylor & Francis Web site at
http://www.taylorandfrancis.com
and the CRC Press Web site at
http://www.crcpress.com
Contents
Acknowledgments xv
Authors xvii
Acronyms And AbbreviAtions xix
chApter 1 the rise of ip-bAsed voice And the need
for globAl ip telephony reAchAbility 1
1.1 Introduction 1
1.2 New Challenges on VoIP Service Offerings 2
1.3 Why Global IP Telephony Reachability Is Needed 3
1.4 The VoIP Protocols Jungle 5
1.4.1 Overview 5
1.4.2 SIP 5
1.4.3 SDP 5
1.4.4 RTP/RTCP 5
1.4.5 SIP-I 6
1.4.6 SIP-T 6
1.4.7 BICC 7
1.4.8 IAX 7
1.4.9 DUNDi 8
1.4.10 TRIP 8
1.4.11 TGREP 9
1.4.12 ENUM 9
1.5 What Is This Book about? 9
v
vi Contents
pArt i ip telephony: overview
chApter 2 trAffic AnAlysis voip versus pstn/mobile 13
2.1 This Chapter at a Glance 13
2.2 Fixed VoIP 13
2.2.1 Focus on France 17
2.2.2 Focus on Portugal 19
2.2.3 Focus on Latin America 20
2.2.4 Focus on South Korea 20
2.2.5 Focus on the United States 21
2.3 Mobile VoIP 21
2.4 Peer-to-Peer (P2P) 23
References 24
chApter 3 ims: ip multimediA subsystem 27
3.1 What Is IMS? 27
3.1.1 Transport Layer 28
3.1.2 Control Layer 28
3.1.3 Service Layer 29
3.2 IMS Functional Elements 29
3.2.1 Call Session Control Function (CSCF) 29
3.2.2 Home Subscription Server (HSS) 32
3.2.3 PSTN Gateways 32
3.2.4 Application Servers (AS) 33
3.2.5 IMS Flow Examples 33
References 35
Further Reading 35
chApter 4 tispAn overview 37
4.1 Overview 37
4.1.1 Brief History Concerning NGN
Standardization 37
4.1.2 Basic Principles 38
4.1.3 TISPAN Functional Architecture 39
4.1.4 Brief Description of the Subsystems 40
4.1.4.1 Service Level 41
4.1.4.2 Transport Layer 46
4.2 Protocols 50
4.2.1 SIP 51
4.2.2 Diameter 52
4.2.3 H.248 55
4.3 Interface between NGN and Legacy Networks 56
4.3.1 PSTN/ISDN Interconnection 57
4.3.2 IP-Based External Network Interconnection 58
4.3.3 Interoperator IP Backbone Network 59
References 61
Contents vii
chApter 5 interconnection prActices in pstn 63
5.1 Overview 63
5.2 Interconnection Services Access 63
5.2.1 Interconnection Points 64
5.2.2 Interconnection Circuits 64
5.2.3 Interconnection Services 64
5.2.4 Signaling 66
5.3 Traffic Interconnection Circuits 68
5.3.1 Interconnection through Circuits Provided
by Other Operators 69
5.4 Traffic Registration 69
5.5 Interconnection Planning and Developing 69
5.5.1 Interconnection Establishment Previous
Information 71
5.6 Services and New Services 71
5.7 Security and Protection 72
5.8 Numbering 72
5.9 Technical Characteristics 73
5.9.1 Interconnection Circuits Transmission
Characteristics 73
5.9.2 Signaling Interfaces between Exchanges 73
5.9.2.1 Signaling Network Structure 74
5.9.2.2 Synchronization between
Networks 74
5.9.3 Quality of Service (QoS) 75
5.9.4 Operation, Management, and Maintenance 75
5.10 Capacity Resale 75
5.11 Prices 76
5.12 Transit 76
5.13 PSTN Interconnection: Economic Models 77
5.13.1 CPNP (Calling Party Network Pays) 78
5.13.2 BAK (Bill and Keep) 79
5.13.3 Optimize Interconnection Costs 79
References 81
Further Reading 82
chApter 6 roAming prActices in mobile networks 83
6.1 Overview 83
6.2 Roaming 83
6.3 Types of Roaming 86
6.4 Roaming Agreements 88
6.5 Roaming Data 91
6.6 IMS Roaming 94
References 94
viii Contents
chApter 7 interconnection prActices in gprs
networks 97
7.1 Interconnection Practices in GPRS Networks 97
7.2 IMS Interconnection 101
7.2.1 Requirements for Voice Calls 105
7.2.2 SIP Profile 106
7.2.3 Advanced Services 106
References 107
pArt ii ip telephony interconnection:
requirements And business model
chApter 8 terminology And definitions 111
8.1 VoIP Service Providers and Telephony Service
Providers 111
8.2 VoIP Service Providers 114
8.2.1 Traditional Service Providers 114
8.2.2 VoIP Service Providers à la Internet 115
8.3 Definitions 116
8.3.1 Address of Record 116
8.3.2 Address of Contact 116
8.3.3 Back-to-Back User Agent (B2BUA) 116
8.3.4 Call 117
8.3.5 Initiator, Calling Party, Caller 117
8.3.6 Invitee, Invited User, Called Party, Callee 117
8.3.7 Registrar 117
8.3.8 End Point 117
8.4 IP Network Provider and Service Provider 117
8.5 IP Telephony Administrative Domain (ITAD) 118
8.5.1 Proxy Server (PS) 119
8.5.2 Location Server (LS) 119
8.5.3 Interconnection Node (IN) 120
8.5.3.1 Signaling Path Border Element
(SBE) 120
8.5.3.2 Data Path Border Element 120
8.6 IP Telephony Administrative Domain and
Autonomous Systems 121
8.7 Frontiers between ITADs and ASs 122
8.8 Adjacent Domains 124
8.9 Balanced/Unbalanced Traffic 124
8.10 Symmetric/Asymmetric Telephony Paths 125
8.11 Interconnection and Peering 125
8.12 Anonymization 126
8.13 Assumptions 126
References 127
Contents ix
chApter 9 business Actors And relAtionships 129
9.1 Panorama of Main VoIP Service Providers 129
9.1.1 Incumbent Operators 130
9.1.2 “Virtual” VoIP Operators 131
9.1.3 Proprietary Third-Party VoIP Service
Providers 132
9.2 Cooperation Agreements between
Different Types of VoIP Service Providers 133
9.3 Business Actors Involved in VoIP Interconnection 133
9.3.1 Customer 134
9.3.2 End User 135
9.3.3 Service Provider 136
9.3.4 Network Provider 139
9.4 Business Relationships 140
9.4.1 SLA (Service Level Agreement) 140
9.4.2 CPA (Connectivity Provisioning
Agreement) 140
9.4.3 NIA (Network Interconnection Agreement) 142
9.4.4 SIA (Service Interconnection Agreement) 142
9.4.5 Conclusion 143
References 144
chApter 10 ip telephony interconnection:
service requirements 145
10.1 Introduction 145
10.2 Telephony Service Providers: Toward Global IP
Telephony Services 145
10.2.1 No Assumption on the Intraprovide Service
Engineering 146
10.2.2 Support of Various Interconnection Models 146
10.2.3 IP Version Agnostic 146
10.2.4 Global Coverage 147
10.2.5 Support of Numbering Schemes Other
than E.164 147
10.2.6 Discovery of Remote VoIP Service Providers
and Their Capabilities 148

10.2.7 Service Interconnection Agreement
Flexibility 149
10.2.8 Interoperability 149
10.2.9 Exchange of Homogenous IP Telephony
Routing Data 149
10.2.10 Avoid Signaling Loop 150
10.2.11 Ability to Configure the Call Route
Selection Process 150
10.2.12 Support of Multiple Interprovider Telephony
Routes 150
x Contents
10.2.13 Optimization of Signaling Paths and
Media Paths 150
10.2.14 Resilience and Availability of the VoIP
Service at the Service and Control Layers 151
10.2.15 Synchronize Service Layer and Control
Layer 151
10.2.16 Ability to Detect IP Network Provider Spirals 151
10.2.17 Ability to Evaluate the QoS Treatment
When Selecting a Given Inter-ITAD Path 152
10.2.18 Operation and Maintenance (O&M) 152
10.2.19 Charging and Billing 152
10.2.20 Interprovider Interconnection Agreements
Assurance and Monitoring 152
10.2.21 Support of Import and Export Policies 153
10.2.22 Security 153
10.2.23 Protect against SPAM over Telephony
(SPIT) 156
10.2.24 Support of Privacy and Confidentiality 156
10.2.25 No Assumption on the Negotiated Media
Session 157
10.2.26 Load 157
10.2.27 Path-Coupled and Path-Decoupled Models 157
10.2.28 Planned Maintenance Operations 157
10.3 Customer Requirements 157
10.3.1 Global Reachability 157
10.3.2 Transparency of Interdomain Media
Sessions 158
10.3.3 Quality of Service (QoS) 158
10.3.4 Cost 159
10.3.5 Reliability and Robustness 159
10.3.6 Ability to Evaluate the QoS Provided by the
VoIP Service 160
10.3.7 Service Mobility and Roaming 160
10.3.8 Confidentiality and Privacy 161
10.3.9 Anonymization and Customization 161
10.3.10 Freedom of CODEC Usage 162
10.3.11 Free to Subscribe to a Service Offering 162
10.3.12 Service Not Bound to a Specific Interface 162
10.3.13 Environmental Impact 163
10.3.14 Support of Emergency Calls 163
10.3.15 Ability to Support Heterogeneous Calls 163
10.3.16 SLA Verification 164
References 164
Further Readings 165