TABLE OF CONTENTS Some, but for sure not all, details of the SIP protocol are discussed in Appendix A. All normative and/or development work should make direct and explicit reference to the latest IETF/RFC documentation.
Because the theme of this book is end-to-end VoIP service mechanisms, we provide a view into some of the SIP details in the material that follows. We see SIP and IPv6 as two key enabling capabilities for 3G VoIP being introduced in the next 2 3 years. In fact, we see the issue around IPv6 as to "when" rather than "if." However, nothing discussed in this book precludes the continued use of IPv4, anymore than digital PSTN switching/transmission (including ISDN and DSL) has completely eliminated analog telephone systems still in use is some locations in the U.S. and in the rest of the world.
Appendix
