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Mastering FreeSWITCH

You're reading from  Mastering FreeSWITCH

Product type Book
Published in Jul 2016
Publisher Packt
ISBN-13 9781784398880
Pages 300 pages
Edition 1st Edition
Authors (8):
Russell Treleaven Russell Treleaven
Profile icon Russell Treleaven
Seven Du Seven Du
Profile icon Seven Du
Darren Schreiber Darren Schreiber
Profile icon Darren Schreiber
Ken Rice Ken Rice
Profile icon Ken Rice
Mike Jerris Mike Jerris
Profile icon Mike Jerris
Kalyani Kulkarni Kalyani Kulkarni
Profile icon Kalyani Kulkarni
Florent Krieg Florent Krieg
Profile icon Florent Krieg
Charles Bujold Charles Bujold
Profile icon Charles Bujold
View More author details

Table of Contents (21) Chapters close

Mastering FreeSWITCH
About the Authors
About the Reviewers
1. Typical Voice Uses for FreeSWITCH 2. Deploying FreeSWITCH 3. ITSP and Voice Codecs Optimization 4. VoIP Security 5. Audio File and Streaming Formats, Music on Hold, Recording Calls 6. PSTN and TDM 7. WebRTC and Mod_Verto 8. Audio and Video Conferencing 9. Faxing and T38 10. Advanced IVR with Lua 11. Write Your FreeSWITCH Module in C 12. Tracing and Debugging VoIP 13. Homer, Monitoring and Troubleshooting Your Communication Platform Index

Encrypting (S)RTP via ZRTP (key exchange in RTP)

ZRTP is a method for the end-to-end exchange of encryption keys. Caller and callee will directly exchange the keys that will be used to encrypt the audio stream, without any third-party intervention. No proxy is involved; no information is exchanged in SIP(S) or SDP: Key exchange is peer-to-peer via Diffie-Hellmann, in the RTP stream itself, in its initial phase.

ZRTP is compiled by default in FreeSWITCH. If clients support ZRTP, the session will be encrypted in the safest mode possible.

ZRTP is a young protocol, and is already implemented by some softphones (Blink, CSipSimple, iCall, Jitsi, Linphone, Phoner, SFLPhone, Twinkle, Zfone, and Zoiper has announced) but by almost no hardphone or ATA.

There are two ways to solve the lack of hardware devices implementing ZRTP. If you're using a softphone that does not support ZRTP, you can install on the client machine "Zfone", a software utility that will act as a "filter", encrypting and decrypting...

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