[muppetmaster]

Abstract

The Session Initiation Protocol (SIP) is a signaling protocol with great significance to the telecommunications industry. This article provides a general and technical introduction to SIP, and shows how SIP is an important enabler of telecommunication solutions.
Introduction

I once had a great idea for a piece of software that would "float" on top of an application, providing assistance. No, this would not be a dumb "help" system. It would be a live technical support agent, conferenced in over the Internet. At the time I was told "there are no tools, libraries, protocols, or bandwidth for doing that!"

Times have changed.

Many people have broadband at home, over DSL, cable, and other technologies. Good quality tools and libraries abound, both commercial and open source. Standards enable applications. Now is the time for the cool ideas to be executed.

http://dev2dev.bea.com/pub/a/2005/09...ip-part-1.html