Voice Over IP

ANOTHER LOOK AT THE LAYERED ARCHITECTURE FOR VoIP

We have now assimilated enough information to have another look at the VoIP protocol stack that was introduced in Chapters 1 and 2, as depicted in Figure 6-1. In this chapter, we will adjust the model described in the introductory chapters and provide some more details. For this part of the book, I am going to focus on layers 1 and 2 of this model.

In Chapter 5, the roles of ISDN, ADSL, and HFC were explained. This chapter examines the V Series modems, as well as the layer-2 protocols shown here. You might wish to refer back to Figure 6-1 as you read this chapter.

Figure 6-1. The VoIP layered protocol suite