In the beginning of the book we talked about legacy. The more things change, the more everybody wants it to stay the same. It's just a part of how technology evolution works. Our cars still pretend to have speedometer needles; the graphics on your favorite website look like an old-fashioned set of buttons and switches. We as a society also try to live by the motto: "If it ain't broke, don't fix it!" The same principle applies even to things that seem relatively modern, like "how we get on the Internet". Most of us would prefer to remain blissfully unaware of the details when it comes to how all of our fancy gizmos make it onto the Internet. Those of us who take the plunge into the exciting world of IP Telephony will not make it very far before coming face to face with a fearsome beast known as NAT (Network Address Translation).
In this chapter we will discuss:
A brief introduction to NAT, including a little history
The four pitfalls of NAT
The settings in FreeSWITCH...