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

SIP, RTP, SDP, RTCP, OH MY!


To troubleshoot VoIP you need to understand at least a little bit of SIP and related protocols. That's the sad truth. You will get nothing from packet-capture and analysis if you don't understand the basics of the protocols.

You can certainly send the file containing the captured packets to someone who's more SIP conversant. If you want to take that option, read the following section about the tools you can use to generate a pcap file with all the relevant info.

The other option is to learn it yourself before problems occur, using sipgrep and sngrep (they make for a colorful, easy and complete toolset) to visualize protocol packets, and one of the many books/tutorials out there as reference. Do test calls and watch what happens. You'll see that there are regularities and meanings, and after a while you'll know most patterns and what to look for. You'll be ready when the time comes.