9.1 INTRODUCTION9.2 SWITCHING AND WHY IT IS IMPORTANT9.3 THREE TYPES OF SWITCHING9.4 QUALITY OF SERVICE9.5 SPECIAL SERVICES9.6 SWITCHING IN ONE OR MORE STAGES9.7 COST MODEL FOR SWITCH IMPLEMENTATIONS9.8 CROSSBAR SWITCH CONCEPT9.9 OPTICAL CROSSBAR SWITCHES9.10 DIGITAL ELECTRONIC CROSSBAR SWITCHES9.11 MULTISTAGE CROSSBAR-BASED SWITCHES9.12 DESIRABILITY OF SINGLE-STAGE FABRICS AND LIMITS TO MULTISTAGE FABRICSKEY POINTSREFERENCES