Written by one of the most respected members of the telecommunication community, this book covers the dramatic changes of the past two decades in the field of telecommunications and the rapidly evolving network technologies of the future. Both packet switching, used to improve data communications, and circuit switching, used in telephone networks, are covered in detail from qualitative discussion to performance analysis. A final chapter devoted to combined aspects of both technologies and to future integrated communication networks rounds out the book. This book will prove to be invaluable for telecommunication engineers, managers, network planners, system analysts, designers, programmers, and other technical personnel interested in current and future aspects of telecommunications