Chapter 7. Understanding Telephony

Utility is when
you have one telephone, luxury is when you have two, opulence is when you have threeand
paradise is when you have none .

Doug Larson

We're now going to take a break from Asterisk for a chapter or two, because we want to spend some time discussing the technologies with which your Asterisk system will need to interface. In this chapter, we are going to talk about some of the technologies of the traditional telephone networkespecially those that people most commonly want to connect to Asterisk. ^[*] While tomes could be written about the technologies in use in telecom networks, the material in this chapter was chosen based on our experiences in the community, which helped us define the specific items that might be most useful. Although this knowledge may not be strictly required in order to configure your Asterisk system, it will be of great benefit when interconnecting to systems (and talking with people) from the world of traditional telecommunications.

^[*] We'll discuss Voice over IP in the next chapter.