Book Image

Mastering FreeSWITCH

By : Russell Treleaven, Seven Du, Darren Schreiber, Ken Rice, Mike Jerris, Kalyani Kulkarni, Florent Krieg, Charles Bujold
4 (1)
Book Image

Mastering FreeSWITCH

4 (1)
By: Russell Treleaven, Seven Du, Darren Schreiber, Ken Rice, Mike Jerris, Kalyani Kulkarni, Florent Krieg, Charles Bujold

Overview of this book

FreeSWITCH is one of the best tools around if you’re looking for a modern method of managing communication protocols through a range of different media. From real-time browser communication with the WebRTC API to implementing VoIP (voice over internet protocol), with FreeSWITCH you’re in full control of your projects. This book shows you how to unlock its full potential – more than just a tutorial, it’s packed with plenty of tips and tricks to make it work for you. Written by members of the team who actually helped build FreeSWITCH, it will guide you through some of the newest features of version 1.6 including video transcoding and conferencing. Find out how FreeSWITCH interacts with other tools and APIs, learn how to tackle common (and not so common) challenges ranging from high availability to IVR development and programming advanced PBXs. Great communication functionality begins with FreeSWITCH – find out how and get your project up and running today.
Table of Contents (21 chapters)
Mastering FreeSWITCH
Credits
About the Authors
About the Reviewers
Contributors
www.PacktPub.com
Preface
7
WebRTC and Mod_Verto
Index

Reacting to channel state changes


FreeSWITCH channels are always, deterministically, in one specific state of a finite state machine. There are rules for going from one state to another, and you can ask FreeSWITCH core to alert your module whenever a channel changes state.

There are 12 states a channel can be in (init, routing, execute, hangup, exchange_media, soft_execute, consume_media, hibernate, reset, park, reporting, destroy), plus the state none, which a channel is supposed to never assume.

State changes are important moments, particularly for billing and accounting (start of media flows, hangup), but you may want to trigger some procedures in other cases too, for example, when a channel is parked.

Our implementation first declares which state changes we want to deal with (LOAD function will register this table with FreeSWITCH core), INIT, and HANGUP.

Then it defines the function we'll use to react to those changes (you can have different functions for each state). Inside the function...