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Revised and Updated 2nd Edition

       Advanced Networks Set

      coordinated by

      Guy Pujolle

      Volume 1

      Software Networks

       Virtualization, SDN, 5G and Security

      Guy Pujolle

First edition published 2015 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc., © ISTE Press Ltd 2015.

      This edition published 2020 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

      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 only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

      ISTE Ltd

      27-37 St George’s Road

      London SW19 4EU

      UK

       www.iste.co.uk

      John Wiley & Sons, Inc.

      111 River Street

      Hoboken, NJ 07030

      USA

       www.wiley.com

      © ISTE Ltd 2020

      The rights of Guy Pujolle to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

      Library of Congress Control Number: 2019950464

      British Library Cataloguing-in-Publication Data

      A CIP record for this book is available from the British Library

      ISBN 978-1-78630-458-2

      Introduction

      Currently, networking technology is experiencing its third major wave of revolution. The first was the move from circuit-switched mode to packet-switched mode, the second from hardwired to wireless mode, and finally the third revolution, which we will examine in this book, is the move from hardware to software mode. Let us briefly examine these three revolutions, before focusing more particularly on the third, which will be studied in detail in this book.

I.1. The first two revolutions

      A circuit is a collection of hardware and software elements, allocated to two users – one at each end of the circuit. The resources of that circuit belong exclusively to those two users; nobody else can use them. In particular, this mode has been used in the context of the public switched telephone network (PSTN). Indeed, telephone voice communication is a continuous application for which circuits are very appropriate.

A major change in traffic patterns brought about the first great revolution in the world of networks, pertaining to asynchronous and non-uniform applications. The data transported for these applications make only very incomplete use of circuits, but are appropriate for packet-switched mode. When a message needs to be sent from a transmitter to a receiver, the data for transmission are grouped together in one or more packets,

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