Part II
The Signaling Plane in the IMS
As we saw in Chapter 3 the IMS has a signaling plane and a media plane that traverse different paths. This part of the book (Part II) tackles the signaling plane in the IMS, while Part III tackles the media plane.
We explained in Chapter 2 that one of the goals of the IMS is to use Internet technologies and protocols as much as possible. One of the main advantages of Internet protocols is that they are designed to be general enough to work within a wide range of architectures. While we are mainly interested in showing how these protocols are used in the IMS, it is essential to understand how they are used in other environments as well.
So, we will divide the explanation of every protocol into two chapters. First, we describe how each protocol works in the Internet environment and how it can be extended for use in architectures with different requirements from the public Internet (e.g., the IMS). Once we have introduced a particular protocol and its design principles in a chapter, we can study how that protocol is used in the IMS in the following chapter, which protocol extensions are used, and how that protocol fits into the IMS architecture. Following these steps in the explanation of every protocol gives the reader a broad perspective of the Internet technologies used in the IMS. Understanding the similarities and differences in the operation of a particular protocol on the Internet and in the IMS will help the reader to understand how ...
