Book Image

FreeSWITCH Cookbook

By : Raymond Chandler, Darren Schreiber, Anthony Minessale II, Michael Collins
Book Image

FreeSWITCH Cookbook

By: Raymond Chandler, Darren Schreiber, Anthony Minessale II, Michael Collins

Overview of this book

FreeSWITCH is an open source telephony platform designed to facilitate the creation of voice, chat, and video applications. It can scale from a soft-phone to a PBX and even up to an enterprise-class softswitch.In the FreeSWITCH Cookbook, members of the FreeSWITCH development team share some of their hard-earned knowledge with you in the book's recipes. Use this knowledge to improve and expand your FreeSWITCH installations.The FreeSWITCH Cookbook is an essential addition to any VoIP administrator's library.The book starts with recipes on how to handle call routing and then discusses connecting your FreeSWITCH server to the outside world.It then teaches you more advanced topics like CDR handling, practical examples of controlling FreeSWITCH with the event socket, and configuring many features commonly associated with a PBX installation.
Table of Contents (12 chapters)
FreeSWITCH Cookbook
About the Authors
About the Reviewers

Codec configuration

Codec configuration is very versatile in FreeSWITCH. In IP telephony, there are several differing scenarios for negotiating and choosing codecs. To meet the varying demands, FreeSWITCH has several configurable modes of operation as well as real-time variables that can influence how codec negotiation takes place. Typically the goal should be to reduce transcoding or resampling as much as possible. Transcoding is the case where two sides of the call have different codecs and audio flowing in either direction has to be completely decoded and re-encoded to the opposite channel's format. Resampling is similar but it is required when each side of the call is running at a different sample rate and the audio has to be "resampled" to the correct rate. One or both of these can be necessary depending on where you direct your calls to and how you have your codec configuration set.

Getting ready

The biggest decision to make up front is late-negotiation or early-negotiation. This setting...