Book Image

FreeSWITCH 1.2 - Second Edition

Book Image

FreeSWITCH 1.2 - Second Edition

Overview of this book

FreeSWITCH is an open source telephony platform designed to facilitate the creation of voice and chat-driven products, scaling from a soft-phone to a PBX and even up to an enterprise-class soft-switch. It is always exciting to design and build your own telephony system to suit your needs, but the task is time-consuming and involves a lot of technical skill."FreeSWITCH 1.2" comes to your rescue to help you set up a telephony system quickly and securely using FreeSWITCH. It is rich with practical examples and will give you all of the information and skills needed to implement your own PBX system.You will start with a detailed description of the FreeSWITCH system architecture. Thereafter you will receive step-by-step instructions on how to set up basic and advanced features for your telephony platform.The book begins by introducing the architecture and workings of FreeSWITCH before detailing how to plan a telephone system and then moves on to the installation, configuration, and management of a feature-packed PBX. You will learn about maintaining a user directory, XML dial plan, and advanced dial plan concepts, call routing, and the extremely powerful Event Socket. You will finally learn about the online community and history of FreeSWITCH."FreeSWITCH 1.2" is an indispensable tool for novice and expert alike.
Table of Contents (24 chapters)
FreeSWITCH 1.2
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

The four pitfalls of NAT


There are four basic pitfalls of NAT that everyone should learn. Understand these pitfalls and you will be well-equipped to handle the NAT scenarios that you'll no doubt face:

  • NAT can be there even when you don't know about it. The Internet does not have to be involved.

  • Any two techniques to defeat NAT used together will cancel each other out.

  • Some devices use a SIP ALG (Application Layer Gateway) to defeat NAT.

  • NAT correction techniques can falsely identify a situation and actually make things even worse.

Become familiar with these pitfalls. They are referenced frequently throughout this chapter.

Let's discuss each of these in more detail:

  • NAT can be there even when you don't know it. The Internet does not have to be involved.

    If you are using home Internet service from your cable or telephone company, or even in some cases a business-class service, they may on occasion use NAT to put all of their customers in a separate network and then translate that network to other...