Book Image

FreeSWITCH 1.8

By : Anthony Minessale II, Giovanni Maruzzelli
Book Image

FreeSWITCH 1.8

By: Anthony Minessale II, Giovanni Maruzzelli

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. This book introduces FreeSWITCH to IT professionals who want to build their own telephony system. This book starts with a brief introduction to the latest version of FreeSWITCH. We then move on to the fundamentals and the new features added in version 1.6, showing you how to set up a basic system so you can make and receive phone calls, make calls between extensions, and utilize basic PBX functionality. Once you have a basic system in place, we’ll show you how to add more and more functionalities to it. You’ll learn to deploy the features on the system using unique techniques and tips to make it work better. Also, there are changes in the security-related components, which will affect the content in the book, so we will make that intact with the latest version. There are new support libraries introduced, such as SQLite, OpenSS, and more, which will make FreeSWITCH more efficient and add more functions to it. We’ll cover these in the new edition to make it more appealing for you.
Table of Contents (23 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Pitfalls to avoid


The most frequent Dialplan error made by people new to FreeSWITCH (and by distracted old hands) is without any doubt setting a variable and expecting to be able to check it some lines down for the assigned value. NOOOOOOOOOOOT.

In this book, I am repeating the concept very (too much?) often, trying to leave a mark in your collective consciousness, but let's do it again here:

  • Dialplan is first "traversed" by the call, checking all extensions, conditions, and so on for matches. Only after all the "traversing" is done and completed, are the actions in the TODO list executed.
  • If there are condition matches, then actions will be put in the TODO list.
  • Some of those actions can be "set" actions, actions that assign variables.
  • So, we just added a variable setting action in the TODO list.
  • We then check the variable. Is it STILL OLD (or nonexistent) VALUE.
  • That's because we are still in the traversing phase, we have not yet executed the "set" action.
  • Got it?
  • If you want your "set" action...