Network Convergence. Services, Applications, Transport, and Operations Support. Hu Hanrahan. John Wiley & Sons, Ltd

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5 Network Convergence Services, Applications, Transport, and Operations Support Hu Hanrahan University of the Witwatersrand, Johannesburg, South Africa John Wiley & Sons, Ltd

6 Copyright c 2007 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone (+44) (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on 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, scanning or otherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP, UK, without the permission in writing of the Publisher. Requests to the Publisher should be addressed to the Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England, or ed to permreq@wiley.co.uk, or faxed to (+44) This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Other Wiley Editorial Offices John Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USA Jossey-Bass, 989 Market Street, San Francisco, CA , USA Wiley-VCH Verlag GmbH, Boschstr. 12, D Weinheim, Germany John Wiley & Sons Australia Ltd, 42 McDougall Street, Milton, Queensland 4064, Australia John Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore John Wiley & Sons Canada Ltd, 6045 Freemont Blvd, Mississauga, ONT, L5R 4J3, Canada Library of Congress Cataloging-in-Publication Data Hanrahan, Hu. Network convergence : services, applications, transport, and operations support / Hu Hanrahan. p. cm. Includes bibliographical references and index. ISBN-13: (cloth : alk. paper) ISBN-10: (cloth : alk. paper) 1. Convergence (Telecommunication) 2. Internetworking (Telecommunication) 3. Wireless communication systems I. Title. TK5101.H dc British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN Typeset by the author using L A TEX software. Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire. This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least two trees are planted for each one used for paper production.

7 Contents Preface Acknowledgments Conventions Companion Website Abbreviations Principal Graphic Symbols xiii xv xv xvi xvii xxvii 1 Setting the Context for Evolution and Convergence of Networks Historical Background to Present Networks Defining Present State Using Reference Models Silo Model for Vertically Integrated Networks Present State: Fixed and Mobile Networks with IN Overlay Present State: Data Service in Mobile Networks Present State: The Internet Present State: Enterprise Networking Present State: Switched and Leased-line Services Evolution and Convergence Initial Convergence Examples FeaturesofConvergence The Next Generation Network Concept Conclusion A Framework for Examining Next Generation Networks Characteristics of Evolving Networks Proliferation of Terminals and Access Networks CoreNetworkTypes Evolution of Service Architectures Dealing with Complexity Framework for Evolving Networks Layering Domains Planes Summary of the NGN Framework Examples of Application of Framework Legacy Networks Elements in the Framework

8 vi CONTENTS From Circuit Switch to Softswitch Conceptualising Convergence in Layered Model Drawing the Boundary of the Regulated Domains Digital Video Broadcasting in the Framework Conclusion Software Methodologies for Converged Networks and Services Development of Software Methodologies for ICT Software Processes in the NGN Framework Software Analysis and Design Requirements Functional Entities as Software Elements Physical Entities in the Framework Specification and Description Requirements Modelling High-level Analysis and Design Methods The Reference Model of Open Distributed Processing Model Driven Architecture SDL and MSC A Legacy System Method: UFM Generalising High-level Methods Role of Software Architectures Software Modelling Notations Enterprise and Business Modelling Notation Enterprise Language UML Use Case Diagrams Object and Data Definition Languages UML Class and Object Diagrams Abstract Syntax Notation One Interface Definition Language Classical Telecommunications Protocols Method Calls as Application Protocols IETFText-basedProtocols Hypertext Markup Language Extensible Markup Language Dynamic Modelling Notations Activity, Communication and Robustness Diagrams Message Sequence Charts State Diagrams Connection Models Component and Interface Notations Distributed Systems Network Protocol-based Distributed Systems Remote Method Invocation Web Services Model CORBA-based Systems Creating a Unified Framework

9 CONTENTS vii 4 An NGN: the Managed Voice over IP Network Development of Packet Multimedia Standards Requirements on a Managed Voice Network Properties of Packetised Voice Key Properties of Speech Digitising Speech Reducing the Bit-rate Speech Quality Metrics Audio Processing for Conferencing General Concepts of Multimedia Communications Access Configurations Terminology Generalised Softswitched System Configurations Generalised Multimedia Call Signalling Signalling Plane for Packet Multimedia Real-time Transport Protocol Reliable Signalling Transport in Packet Networks: SCTP The H.323 Suite Development and Structure of H The H.323 Architecture Gateway Decomposition Addressing in H.323 systems H.323 Protocol Stacks Media Gateway Functions and Control Media Gateway Entities Media Gateway Control Protocol: Megaco Media Gateway Control Protocol Multimedia Communications Based on SIP IETF Multimedia Conferencing Protocols Architecture of SIP Multimedia Systems SIP Methods and Modes of Operation Session Description Protocol Use Cases for SIP Supplementary Services in Packet Telephony Supplementary Services in H Call Services in SIP Telephony ITU-T Evolutionary Protocols: BICC Voice on the Internet Conclusion Integrated Enterprise ICT Systems Drivers and Requirements Convergence in the Enterprise Domain Corporate Requirements Modelling Integrated Enterprise ICT Systems

10 viii CONTENTS 5.2 Contributions to Convergence Adoption of Commercial-off-the-Shelf Components TheMultimediaSoftswitch Computer Telephony Integration Enterprise System Software Architecture Network Level Convergence Application and Service Level Convergence Conclusions Legacies and Lessons: Broadband ISDN, TINA and TIPHON LearningfromHistory TheBroadbandISDN B-ISDN Architecture Asynchronous Transfer Mode Call and Connection Control Routing and Call Control Protocols B-ISDN and IN Appraisal of B-ISDN TINA Architecture The TINA Architecture TINA Layers Planes: Hiding Physical Resources TINAandRM-ODP Business Model and Reference Points Generic Business Domains Interdomain Reference Points Business Scenarios TINA Service Architecture Service Architecture: Information Viewpoint Computational Viewpoint: the Service Components Network Resource Architecture Use Case 6: Convert Steam Binding to Network Connection Lessons from TINA for NGNs Achievements of TINA as an NGN Weaknesses of TINA TIPHON Objectives of TIPHON TIPHON Layered Model TIPHON Business Models TIPHON Domain and Interworking Model TIPHON Functional Architecture Registration and Mobility in TIPHON TIPHON Metaprotocol TIPHON Implementation using Established Protocols

11 CONTENTS ix TIPHON and Multimedia Services Appraisal of TIPHON Conclusion Important NGNs: Third Generation Mobile Communication Systems Architectural Concepts Concept of a Public Land Mobile Network Structural Features of a PLNM Geographical Relationships in a PLNM Mobile Communication System Evolution Baseline: the Second Generation Mobile Network Identification of Mobile Network Generations Evolution of the Radio Access Network Development of the MSC Terminals in the 3G Context Services in the CS Domain Mobility Management in the CS Domain Call Handling in 3G Systems Setting Up Bearer Connections in the 3G CS Domain CAMEL-based Services in the CS Domain Packet-switched Domain: GPRS-based Systems GPRS-based Packet-domain Architecture GPRS Support Node Functions Mobility Management in the PS domain Packet Transport in GPRS Protocols Used in GPRS Access and Core GPRSandCAMEL IP Multimedia Subsystem Origins and Objectives of the IMS IMS Architecture and Components IETFProtocolsusedinIMS IMSServiceModel Session Control Value-added IM Services The 3GPP2 All-IP Approach to 3G Networks Conclusion Opening the Network using Application Programming Interfaces Closed Network Evolution Opening the Network BusinessModels The OSA/Parlay Architecture Architectural Concepts API Definition Method and Technology Independence FrameworkInterfacesandUseCases Use Case: Provisioning a Gateway Service Use Cases: An Application Gains Access to a Service Manager 337

12 x CONTENTS 8.5 The OSA/Parlay Gateway Standard Service Capability Features Interface Definition Design Pattern Interaction in Communication-oriented SCFs Communication-orientated Use Cases Call Control and User Interaction Interfaces Concept of a Call in OSA Parlay Interfaces and Interactions Network Event Detection and Reporting Call, Call Leg and Callback Object Creation User Interaction Handling a Triggered Notification Call Supervision Multimedia Media Stream Control Conference Control Data Session Control Generic Messaging Mobility, Account Management and Terminal Capabilities Presence and Availability Charging and Account Management Connection Management OSA/Parlay Data Structures Sample Service ParlayXWebServices The Case for a Simpler API The Parlay X Web Services Architecture Parlay X Web Service Example: Audiocall Parlay X Implementation via OSA/Parlay OSA/Parlay API Implementation Issues Gateway-to-Network Interface Abstraction Revisited Service Deployment Scenarios Service Creation Other Approaches to Open Networks JAIN Open Mobile Alliance Service Environment The Service Delivery Platform Concept Conclusion Operations Support Systems Relationship of OSS/BSS to ICT Systems Evolution of OSS/BSS The OSI Network Management Model IETF Network Management Standards The Telecommunications Management Network The Telecommunications Operations Map Enhancement of the TOM: etom

13 CONTENTS xi 9.5 New Generation OSS Conclusion Migration from Legacy to Next Generation Networks Retrospect Reflecting on Evolution and Convergence The Evolution Metaphor, with Hindsight Market-oriented Objectives Promoting Convergence Technology Migration The Migration Process IsThereaTargetNGN? Whither Fixed Networks? Are Fixed and Mobile Networks Distinct? Fourth Generation Mobile Communication Systems Managing Complexity: Avoiding Pitfalls Do Not Forget the Principles Be Aware of Leaky Abstractions Silos May Still be Created BeAwareofHype Handling The Great Debates Evolution is an Ongoing Process Revisit the Treasure House A Last Word Glossary 423 References 431 Index 447

15 Preface The present information age is enabled by telecommunications and information technology (IT) and the continued convergence of their services, technologies and business models. Within telecommunications, the historic separations between fixed networks, mobile telephone networks, data communications and enterprise networks are diminishing. The Internet initially supported the academic community but now provides communications for public information services and business IT operations. The Internet depends on telecommunications infrastructure for user access and core networks. Telecommunications increasingly adopts technology developed primarily for the Internet. Within the telecommunications world, the evolution of technology and the enhanced services that can be offered through synergies with IT have been captured in the concept of next generation networks (NGN). This concept does not mean a particular network but rather the process of evolution from present technology and services to new technologies, enabling new services and applications with both telecoms and IT characteristics. The NGN concept also captures the need for structured thinking to deal with the complexity of systems, applications and business models in information and communications technologies (ICT). This book takes as a starting point present day networks, services and operations support and maps their evolution toward specific future forms, collectively termed next generation networks. In the process, we examine the nature, process and results of convergence. Many candidate technologies are offered but few are adopted. The process of assessment, selection and integration of technology is complex, particularly when constraints exist due to the ongoing presence of legacy technology. We therefore examine the process of migration to new technologies. Many recent texts describe various next generation network technologies. The approach of this book is analytical rather than descriptive. We establish concepts, principles and architectural frameworks rather than conventional descriptions of specific technologies. Individual architectures and technologies are depicted within a framework, facilitating comparisons and drawing contrasts and assisting in integrating different technologies to form a system. The framework aids the understanding of next generation networks, their potential for supporting new, enhanced applications and their relationships with legacy networks. We draw analytical and descriptive methods from several sources, as diverse as the classical Intelligent Network, software engineering and selected telecommunications standards. Telecommunications systems must be based on standards. In most cases, standards or draft standards exist for emerging networks and services. The book analyses and explains the concepts and principles of a number of standards for networks, services and applications. The analytical approach supports assessing, designing, integrating and operating technologies in next generation networks. This understanding also informs research and development leading to new technologies.

Next Generation Networks Perspectives and Potentials. Dr Jingming Li Salina LiSalina Consulting, Switzerland Pascal Salina Swisscom SA, Switzerland

Next Generation Networks Perspectives and Potentials Dr Jingming Li Salina LiSalina Consulting, Switzerland Pascal Salina Swisscom SA, Switzerland Next Generation Networks Next Generation Networks Perspectives