Information Technology Reference
In-Depth Information
CHAPTER 1
Traditional Voice Versus Unified Voice
Welcome to the world of voice. No, not VoIP; you're not there yet. Before you can enter
that world, a foundation must be laid. The traditional telephony network has been in place
since the early 1900s, and it is not going to disappear overnight. Thus, until then, the new
VoIP networks must integrate with traditional telephony networks. To perform this inte-
gration, you must have a basic understanding of the world of traditional voice telephony.
This chapter walks you through the foundations of the public switched telephone network
(PSTN), private branch exchange (PBX) systems, and analog and digital circuitry.
“Do I Know This Already?” Quiz
The “Do I Know This Already?” quiz allows you to assess whether you should read this
entire chapter or simply jump to the “Exam Preparation Tasks” section for review. If you
are in doubt, read the entire chapter. Table 1-1 outlines the major headings in this chapter
and the corresponding “Do I Know This Already?” quiz questions. You can find the an-
swers in Appendix A, “Answers Appendix.”
Table 1-1
“Do I Know This Already?” Foundation Topics Section-to-Question Mapping
Foundation Topics Section
Questions Covered in This Section
Where It All Began: Analog Connections
1-3
The Evolution: Digital Connections
4-9
Understanding the PSTN
10
The New Yet Not-So-New Frontier: VoIP
11-13
1. Analog phones connected to the PSTN typically use which of the following signal
types?
a.
Loop start
b.
Ground start
c.
CAS
d.
CCS
 
 
 
 
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