pakangas, Rolf Svanbäck, Roger Förstrom, and Stefan Von Schantz. Their encouragement was essential in the first stages of the book. They together with Carl Gunnar Perntz and Olle Viktorsson, from Ericsson Sweden, let me go to Columbia University in New York to work together with Professor Schulzrinne when I was fin- ishing writing SIP Demystified. Professor Schulzrinne's advice and guidance has been very important to me since I began working on SIP-related issues, when SIP was still a brief Internet draft within the MMUSIC working group. Miguel Angel García and Jonathan Rosenberg provided guidance and detailed comments. Their reviews of the manuscript contributed to improve the final product. Last but not least, Marjorie Spencer, my editor at McGraw-Hill, did a terrific work on the manuscript. She deserves recognition for her impact on the final manuscript. She provided new ideas and different points of view that helped make the technical explanations contained in this book clearer to readers with all types of backgrounds. Copyright 2002 The McGraw-Hill Companies, Inc. Click Here for Terms of Use. For more information about this title, click here CONTENTS Preface Foreword Chapter 1 Signalling in the Circuit-Switched Network The Origins of Circuit-Switching Characteristics of Circuit-Switching Strengths of Circuit-Switching Weaknesses of Circuit-Switching Introduction to Signalling FDM and In-band Signalling Analog Transmission Digital Transmission Time Division Multiplexing Digital Signalling Systems Access Signalling Trunk Signalling The Paradigm Behind SS7 Conclusions Chapter 2 Packet Switching, IP, and the IETF Packet Switching Strengths of Packet Switching Weaknesses of Packet Switching IP and the Internet Paradigm IP Connectivity Intelligence Pushed to the End Systems End-to-End Protocols General Design Issues History of the Internet Protocol Development Process Origins of the Request For Comments (RFCS) Coordination Bodies The IETF The IESG The Technical Work IETF Specifications: RFCs and I-Ds Copyright 200