Telecommunications Performance Engineering ISBN:0863413412 by Roger Ackerley (ed) Institution of Electrical Engineers © 2004 (288 pages) This book provides an insight into the rich diversity of techniques, tools and knowledge used in performance engineering, covering the whole life cycle-from design through to operation of both networks and systems Table of Contents Telecommunications Performance Engineering Preface Contributors Performance—A Chapter 1 Retrospective View Traffic Characterisation Chapter 2 and Modelling Potential Interactions Chapter 3 - Between IP-dial and Voice Traffic on the PSTN Techniques for the Study Chapter 4 of QoS in IP Networks Performance Modelling— Chapter 5 - What, Why, When and How Performance Testing—A Case Study of a Chapter 6 Combined Web/Telephony System Adaptive Network Chapter 7 Overload Controls Realising Effective Chapter 8 - Intelligent Network Overload Controls Capacity Planning for Chapter 9 Carrier-Scale IP Networks Performance Monitoring Chapter 10 - for In-Life Capacity Management Performance Health Chapter 11 Check Performance and the Chapter 12 Broadband Window Index List of Figures List of Tables Back Cover Service quality and cost control are critical success factors for the communications industry and performance engineering is vital in achieving both It enables service quality to be “built in” to products; cost control is achieved by addressing potential problems at an early stage, before the costs to remedy problems rise and large failure costs are incurred Telecommunications Performance Engineering includes both introductory material, giving a comprehensive overview of the subject area, and in-depth case studies illustrating the latest tools and techniques Performance engineering throughout the whole lifecycle is discussed, including modeling, measurement, testing and capacity management In addition, the book covers cutting-edge information and technology on the designs used to protect the performance levels of overloaded networks A wide range of system and network applications are covered, from broadband, IP networks, and intelligent networks providing telemarketing services to combined Web/telephony systems, operational support systems and call centers This book is essential reading for communications managers, designers, performance engineers and students About the Editor Roger Ackerley (AFIMA, MSc, BA (Oxon)) is one of the UK’s leading performance engineers He obtained his Masters degree in Telecommunications Engineering and has applied his skills to a wide range of applications for over 20 years working for BT where he currently leads the Critical Solutions team within BT Exact’s Performance Engineering Department Roger is known internationally in his field through his participation at conferences both as presenter and session chair and through his standards work His papers cover a range of subjects from hysteresis effects in networks to overall grade-of-service Telecommunications Performance Engineering Roger Ackerley The Institution of Electrical Engineers Published by: The Institution of Electrical Engineers, London, United Kingdom Copyright © 2003 British Telecommunications plc This publication is copyright under the Berne Convention and the Universal Copyright Convention All rights reserved Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, this publication may be reproduced, stored or transmitted, in any forms or by any means, only with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency Inquiries concerning reproduction outside those terms should be sent to the publishers at the undermentioned address: The Institution of Electrical Engineers, Michael Faraday House, Six Hills Way, Stevenage, Herts SG1 2AY, United Kingdom While the authors and the publishers believe that the information and guidance given in this work are correct, all parties must rely upon their own skill and judgment when making use of them Neither the authors nor the publishers assume any liability to anyone for any loss or damage caused by any error or omission in the work, whether such error or omission is the result of negligence or any other cause Any and all such liability is disclaimed The moral rights of the authors to be identified as authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988 British Library Cataloguing in Publication Data A catalogue record for this product is available from the British Library 0-86341-341-2 Preface With the consolidation of the communications technology industry, there is renewed focus on cost reduction, maximising usage of resources and delivering improved quality-of-service to the customer At the same time great technological change is producing an explosion of new applications, and therefore new performance problems to be solved Furthermore, competitive and regulatory pressures on the industry continue to rise Risk management is now key as technical and commercial risks are balanced against the need to meet market opportunities on time and to budget These technology, market, business and customer service drivers are all increasing the need for performance engineering Whenever resources are shared there are performance questions to be answered and a performance engineering job to be done Typical questions are: How can the solution be designed to meet these delay and loss requirements? How does it scale and what are the ‘break points’? Where are the potential bottle-necks? What control system is required to optimise performance when the platform is overloaded? How do we ensure that the solution performs as designed when it goes live? How will performance and capacity be managed and what measurements are required to do this? The aim of this book is to provide an insight into the rich diversity of techniques, tools and knowledge used to address these types of question The chapters cover the whole of the life cycle from design through to operation of both networks and systems and are written by technical experts currently actively working in the respective areas The subject of performance engineering is divided into five parts: introduction; modelling, measurement and testing; overload control; in-life performance; epilogue The first part provides an introduction to the subject of performance engineering by means of an historical perspective covering more than two decades given in Chapter 1 Over this time applications have changed out of all recognition — for example, from designing gradings for electromechanical exchanges to ensuring quality-of-service in IP networks Perhaps surprisingly, some techniques are as relevant today as they were in the 1970s, while a productive relationship between academics and practitioners continues to produce new methods This chapter illustrates what drives performance engineering work and explains why it still exists as a discipline today and is needed even more than in the past The second part describes the essential performance engineering techniques of modelling, measurement and testing Performance modelling provides the ability to predict performance through a quantitative understanding of how varying demand affects the behaviour of a system or network Without it, there is no understanding and merely the process-driven reactions to faults and problems resulting in endless, haphazard experiments to provide a fix An overview together with the related subject of traffic characterisation is presented in Chapter 2 The interaction between new services and technologies and existing platforms will provide many performance engineering challenges over the next few years The rapid introduction of widespread Internet access in the UK through IP-dial required some re-engineering of the PSTN based on the modelling described in Chapter 3 There are critical IP network performance issues remaining to be resolved, and this area therefore continues to be an active area for the application of both analytical and simulation modelling Chapter 4 provides examples of how modelling is used to provide an understanding of quality of service in IP networks, and how measurement is used as a complementary technique to validate modelling and discover new factors that have not previously been considered As shown in Chapter 5, modelling can also be used as a decision support tool for in-life systems A case-study is presented in Chapter 6 illustrating the role of testing in ensuring that systems meet their performance requirements when they go live Performance testing is becoming more critical as solutions are developed through the integration of separate application components, and the current economic pressures tend to push the identification and resolution of performance issues further down the supplier chain This could be despite performance modelling earlier in the life cycle, or perhaps because there wasn't any! Testing is usually the last opportunity to address these before they become operational issues with consequentially higher failure costs The third part concerns the design of overload control There are times such as during civil emergencies, media-stimulated events, adverse natural conditions or failures when demand for resources is considerably greater than normal The simplest solution is to over-provide capacity to meet the greatest possible demand, but this is usually uneconomic An alternative is to provide effective overload control, which is perhaps one of the most complex areas of design and therefore often with long development times Chapter 7 introduces a generic network solution, while Chapter 8 gives an example of a successful implementation The fourth part relates to the in-life performance of networks and systems: Starting with Capacity Planning, Chapter 9 shows how performance engineering techniques can be employed to address the challenge of planning large IP networks to provide the required performance and Chapter 10 explains the methodology developed over several years to manage the capacity of a sophisticated platform employed to deliver telemarketing services Then the concept of a ‘Performance Health Check’ is portrayed in Chapter 11 The described high-level techniques are used primarily to identify performance risks and issues The final part, Chapter 12, provides a futurologist's view on the performance implications of delivering broadband services — a fitting epilogue I would like to thank my colleagues who have contributed enthusiastically as authors, reviewers and editors to produce this book I hope you enjoy reading it and gain a greater understanding of performance engineering and its relevance to the world of communications and beyond Roger Ackerley Critical Solutions Performance, BT Exact roger.ackerley@bt.com ... Study of these, and the classification of the flips in terms of the limited number of possible mathematical catastrophes, is interesting but essentially sterile: it is only a knowledge of the actual dynamics of the. .. A variety of more-or-less elegant techniques and approximations arose to analyse these; and the theory reached its final flowering in the early 1970s, with the development of Jacobaeus and other methods, the study of nonblocking and rearrangeable networks,... measurements are required to do this? The aim of this book is to provide an insight into the rich diversity of techniques, tools and knowledge used to address these types of question The chapters cover the whole of the life cycle from design