SWITCHING AND TRAFFIC THEORY FOR INTEGRATED BROADBAND NETWORKS

Transcription

1 SWITCHING AND TRAFFIC THEORY FOR INTEGRATED BROADBAND NETWORKS

2 THE KLUWER INTERNATIONAL SERIES IN ENGINEERING AND COMPUTER SCIENCE COMMUNICATIONS AND INFORMATION THEORY Consulting Editor Robert Gallager Other books in the series: Digital Communications. Edward A. Lee, David G. Messer Schmitt ISBN An Introduction to Cryptology. Henk C.A. van Tilborg ISBN Finite Fields for Computer Scientists and Engineers. Robert J. McEliece ISBN An Introduction to Error Correcting Codes With Applications. Scott A. Vanstone and Paul C. van Oorschot, ISBN Source Coding Theory. Robert M. Gray ISBN

3 SWITCHING AND TRAFFIC THEORY FOR INTEGRATED BROADBAND NETWORKS by Joseph Y. Hui Rutgers University foreword by Robert G. Gallager SPRINGER SCIENCE+BUSINESS MEDIA, LLC

4 Library of Congress Cataloging-in-Publication Data Hui, Joseph yu Ngai. Switching and traffic theory for integrated broadband networks / by Joseph Y. Hui. p. cm. (The Kluwer international series in engineering and computer science. Communications and information theory) Includes bibliographical references. ISBN ISBN (ebook) DOI / Telecommunication switching systems. 2. Broadband communication systems. I Titi* n. Series. TK5103.8H dc CIP Copyright 1990 by Springer Science+Business Media New York Originally published by Kluwer Academic Publishers in 1990 Tenth Printing Softcover reprint of the hardcover 1st edition 1990 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, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher, Springer Science+Business Media, LLC. This printing is a digital duplication of the original edition.

5 CONTENTS FOREWORD PREFACE ix xi Chapter 1. Integrated Broadband Services and Networks An Introduction 1.1 Communication Networking 1.2 Broadband Technologies 1.3 Broadband Services 1.4 To Integrate or Not to Integrate 1.5 Outline of the Book 1.6 Exercises 1.7 References PART I: SWITCHING THEORY Chapter 2. Broadband Integrated Access and Multiplexing 2.1 Time Division Multiplexing for Multi-Rate Services 2.2 The Synchronous Transfer Mode 2.3 The Asynchronous Transfer Mode 2.4 Time Division Multiplexing Techniques for Bursty Services 2.5 Switching Mechanisms by Time or Space Division 2.6 Time Multiplexed Space Division Switching 2.7 Appendix-What is in a Label? 2.8 Exercises 2.9 References Chapter 3. Point-to-Point Multi-Stage Circuit Switching 3.1 Point-to-Point Circuit Switching 3.2 Cost Criteria for Switching 3.3 Multi-Stage Switching Networks

6 vi Contents 3.4 Representing Connections by Paull's Matrix Strict-Sense Non-Blocking Clos Networks Rearrangeable Networks Recursive Construction of Switching Networks The Cantor Network Control Algorithms Exercises References 82 Chapter 4. Multi-Point and Generalized Circuit Switching Generalized Circuit Switching Combinatorial Bounds on Crosspoint Complexity Two Stage Factorization of Compact Superconcentrators Superconcentrators and Distribution Networks-A Dual Construction of Copy Networks Construction of Multi-Point Networks Alternative Multi-Point Networks Exercises References 111 Chapter 5. From Multi-Rate Circuit Switching to Fast Packet Switching Depth-First-Search Circuit Hunting Point-to-Point Interconnection of Multi-Slot TOM Fast Packet Switching Self-Routing Banyan Networks Combinatorial Limitations of Banyan Networks Appendix-Non-Blocking Conditions for Banyan Networks Exercises References 136 Chapter 6. Applying Sorting for Self-Routing and Non-Blocking Switches Types of Blocking for a Packet Switch 140

7 Contents vii 6.2 Sorting Networks for Removing Internal Blocking 6.3 Resolving Output Conflicts for Packet Switching 6.4 Easing Head of Line Blocking 6.5 A Postlude-Integrated Circuit and Packet Switching 6.6 Appendix-Self-Routing Multi-Point Switching 6.7 Exercises 6.8 References PART II: TRAFFIC THEORY Chapter 7. Terminal and Aggregate Traffic 7.1 Finite State Models for Terminals 7.2 Modeling of State Transitions 7.3 Steady State Probabilities 7.4 Superposition of Traffic 7.5 Traffic Distribution for Alternating State Processes 7.6 Traffic Distribution for Poisson Processes 7.7 Broadband Limits and The Law of Large Numbers 7.8 Estimating the Traffic Tail Distribution 7.9 Appendix-Improved Large Deviation Approximation 7.10 Exercises 7.11 References Chapter 8. Blocking for Single-Stage Resource Sharing 8.1 Sharing of Finite Resources 8.2 Truncated Markov Chains and Blocking Probabilities 8.3 Insensitivity of Blocking Probabilities 8.4 The Equivalent Random Method 8.5 Traffic Engineering for Multi-Rate Terminals 8.6 Bandwidth Allocation for Bursty Calls 8.7 Exercises 8.8 References Chapter 9. Blocking for Multi-Stage Resource Sharing 9.1 The Multi-Commodity Resource Sharing Problem

8 viii Contents 9.2 Blocking for Unique Path Routing 9.3 Alternative Path Routing-The Lee Method 9.4 Assumptions for Approximating Blocking Probabilities 9.5 Alternative Path Routing-The lacobaeus Method 9.6 Complexity of Asymptotically Non-Blocking Networks 9.7 Exercises 9.8 References Chapter 10. Queueing for Single-Stage Packet Networks 10.1 The MIMlm Queue 10.2 The MIGII Queue-Mean Value Analysis 10.3 The MIGII Queue-Transform Method 10.4 Decomposing the Multi-Queue/Multi-Server System 10.5 HOL Effect for Packet Multiplexers 10.6 HOL Effect for Packet Switches 10.7 Load Imbalance for Single-Stage Packet Switches 10.8 Queueing for Multi-Cast Packet Switches 10.9 Exercises References Chapter II. Queueing for Multi-Stage Packet Networks 11.1 Multi-Stages of MIMII Queues 11.2 Open and Closed Queueing Networks 11.3 Application to Multi-Stage Packet Switching 11.4 Analysis of Banyan Network with Limited Buffering 11.5 Local Congestion in Banyan Network 11.6 Appendix-Traffic Distribution for Permutations 11.7 Exercises 11.8 References INDEX

9 Foreword The rapid development of optical fiber transmission technology has created the possibility for constructing digital networks that are as ubiquitous as the current voice network but which can carry video, voice, and data in massive qljantities. How and when such networks will evolve, who will pay for them, and what new applications will use them is anyone's guess. There appears to be no doubt, however, that the trend in telecommunication networks is toward far greater transmission speeds and toward greater heterogeneity in the requirements of different applications. This book treats some of the central problems involved in these networks of the future. First, how does one switch data at speeds orders of magnitude faster than that of existing networks? This problem has roots in both classical switching for telephony and in switching for packet networks. There are a number of new twists here, however. The first is that the high speeds necessitate the use of highly parallel processing and place a high premium on computational simplicity. The second is that the required data speeds and allowable delays of different applications differ by many orders of magnitude. The third is that it might be desirable to support both point to point applications and also applications involving broadcast from one source to a large set of destinations. The second major problem is that of traffic analysis or performance analysis for future networks. The roots for this problem again go back to telephony and to data networks, both of which are rooted in queueing theory. The new twists here are, first, that studying traffic flowing through various stages of the switches is more important than studying the traffic on the network links. Next, the heterogeneity of required speeds and allowable delays for different applications is important, and also the possibility of broadcast applications is

10 x Foreword important. The reader will be pleasantly surprised to find that most of the topics here are quite accessible. An undergraduate senior in electrical engineering or computer science certainly has the background (although not necessarily the maturity) to understand switching for future networks as developed in the first half of the book. The traffic analysis in the second half requires quite a bit of facility with probability, but given this facility, the material is again surprisingly accessible. Many of the results here are not found elsewhere in book form and have only appeared relatively recently in journals. Professor Hui, however, has managed to pull all these results together into an integrated whole. There is quite a bit of discussion about engineering constraints and practical aspects of the subject, but it is placed within a conceptual framework that helps the reader develop an overall understanding and intuition for the issues involved in designing high speed networks. There will probably be a large number of books coming out in this area in the next few years, and one hopes that this book will set a standard that these other books will follow. Robert G. Gallager Fujitsu Professor of Electrical Engineering Co-Director, Laboratory for Information and Decision Systems Massachusetts Institute of Technology

11 Preface This is a senior or graduate level textbook intended for students and researchers in three different fields. First and primarily, this book is intended for those in the field of futuristic telecommunication networks. These networks, yet to be implemented and understood completely, provide flexible point-to-point and multi-point communications via media such as voice, data, and video. The economy of these networks relies on the recent advances in broadband transmission and processing technologies. The time has come for us to reexamine the well-established switching and traffic theory for telephone service to heterogeneous services with diverse attributes. This book attempts to frame a modern view of the theory based on the rich traditions of classical telephony. Second, this book is intended for those in the field of parallel computation. The fields of telecommunication switching and parallel computing have traditionally been using methodologies from the other field, enriching both fields in the process. This cross-fertilization is not surprising since communication networks can be used for distributed processing, whereas computer networks can be used for exchange of information. Readers interested in parallel computing should find the switching networks described applicable for the interconnection of a large number of processors. Similarly, teletraffic theory can be applied to computer network and parallel processing performance analysis. Third, this book is intended for those in the field of optical transmission and processing technologies. For making good use of these new technologies, it is helpful to understand the structural, functional, and control attributes of switching networks. These attributes in turn determine how well heterogeneous services may be supported. The relative strength and weakness of these technologies

12 xii Preface should be evaluated with respect to these attributes. Therefore, the proper choice of technologies and their deployment configuration in a communication network affect the variety and quality of services. This book is intended to furnish the necessary background for the optical technologist to build communication subsystems from optical components. This book was developed from course notes for a class taught at the Center for Telecommunications Research at Columbia University. In choosing the topics to cover, the author became keenly aware that a vast but scattered literature exists for classical switching and traffic theory, whereas research in the field of integrated broadband switching is in a fledgling stage. In fact, the feasibility of an integrated network remains a thesis to be proven since none has been implemented on a large scale yet. Some of the criteria for feasibility are yet to be defined. Nevertheless, this book attempts to instill a set of principles which may prove useful for constructing and analyzing integrated broadband networks. No attempt is made for completeness since the subjects covered remain a small subset of the available literature. Yet hopefully, the material should define an essential framework for the field. Most of the material is chosen for its theoretical import, and some sections reflect the research interests of the author as well as recent research activities at Bellcore. Many sections present new results which have not been published before. A first course in Probability is necessary for understanding the material presented. A prior knowledge of communication networks and computer algorithms is helpful but not crucial. To facilitate easier understanding, new and simple proofs are given for most results, supplemented extensively with intuition and illustrations. The material can be taught in one semester, or more leisurely divided into two courses on switching and traffic respectively, with the supplement of recent research papers and the requirement of a term project. A subset of this material may be chosen for a short course for research engineers in the communication industry. A teacher's manual is also available.

13 Preface xiii As the title Switching and Traffic Theory for Integrated Broadband Networks suggests, the book is divided into two parts: Switching Theory (Chapters 2-6), and Traffic Theory (Chapters 7-11). Chapter 1 serves as a prelude by introducing the technology, system, and service aspects of an integrated broadband network. There is a rough correspondence between chapters in the two parts. This correspondence, together with a description of the chapters, is given at the end of chapter 1. This book, as well as my research contributions described therein, is made possible by the gracious and enriching environment of several institutions. Foremost, I would like to thank Bell Communications Research and its management (Eric Nussbaum, Dave Sincoskie, Steve Weinstein, and Pat White) for their generous support during the past years when most of the research and writing were done. I am fortunate to be at this research institution when and where many seeds of the so called broadband revolution fermented. I would also like to thank the Center for Telecommunications Research of Columbia University and its faculty (Aurel Lazar, Henry Meadows, and Mischa Schwartz) for fruitful interactions, and for allowing me to teach the material. Many individuals reviewed the material, including Eric Addeo, Howard Bussey, Fred Descloux, Bob Gallager, Alex Gelman, Shlomo Halfin, Mike Honig, Ram Krishnan, Francois Labourdette, Tony Lee, Bob Li, Victor Mak, Steve Weinstein, Albert Wong, Liang Wu, and two anonymous individuals. Their criticism improved the presentation significantly as well as weeded out many errors. Finally, I want to thank my wife Ruth for her encouragement and care over many weekends and week nights I spent typing away at the terminal, and my little Justin for roaming cheerfully around me in his walker during those times. Without them, life would seem strangely disconnected. Joseph Y. Hui Piscataway, NJ. July, 1989.

14 SWITCHING AND TRAFFIC THEORY FOR INTEGRATED BROADBAND NETWORKS