SIP (Session Initiation Protocol) is the open standard that will make IP telephony an irresistible force in communications, doing for converged services what http does for the Web. SIP Demystified – authored by Gonzalo Camarillo, one of the contributors to SIP development in the IETF—gives you the tools to keep your company and career competitive. This guide tells you why the standard is needed, what architectures it supports, and how it interacts with other protocols. As a bonus, you even get a context-setting background in data networking. Perfect if you’re moving from switched voice into a data networking environment, here’s everything you need to understand: