ZRTP is a protocol from IETF published in April 2011 as rfc6189. ZRTP
describe a key exchange protocol which is used “in-band”. This
helps to interoperates with any SIP/RTP phone and auto-detects
if encryption is supported by other endpoint. When we wish
encryption, it’s very important to still interoperate smootly
with sip agent not supporting SRTP. ZRTP is a must!

Here is the abstract of the rfc:

This document defines ZRTP, a protocol for media path Diffie-Hellman
exchange to agree on a session key and parameters for establishing
unicast Secure Real-time Transport Protocol (SRTP) sessions for Voice
over IP (VoIP) applications. The ZRTP protocol is media path keying
because it is multiplexed on the same port as RTP and does not
require support in the signaling protocol. ZRTP does not assume a
Public Key Infrastructure (PKI) or require the complexity of
certificates in end devices. For the media session, ZRTP provides
confidentiality, protection against man-in-the-middle (MiTM) attacks,
and, in cases where the signaling protocol provides end-to-end
integrity protection, authentication. ZRTP can utilize a Session
Description Protocol (SDP) attribute to provide discovery and
authentication through the signaling channel. To provide best effort
SRTP, ZRTP utilizes normal RTP/AVP (Audio-Visual Profile) profiles.
ZRTP secures media sessions that include a voice media stream and can
also secure media sessions that do not include voice by using an
optional digital signature.

• Jabra UC Voice 150 Mono
• Jabra UC Voice 150 Duo
• Jabra UC Voice 250
• Jabra UC Voice 550 Mono
• Jabra UC Voice 550 Mono
• Jabra BIZ 2400 Mono USB
• Jabra PRO 930
• Jabra PRO 9450
• Plantronics Blackwire C420
• Plantronics Audio 478 USB
• Plantronics BT300 with Voyager PRO UC v2

The already supported devices are listed below:

Plantronics devices:

• Plantronics CS60
• Plantronics Savi Office
• Plantronics BT Adapter
• Plantronics DA45
• Plantronics MCD100
• Plantronics BUA-200

Jabra devices:

• Jabra A330
• Jabra BIZ 620 USB
• Jabra DIAL 520
• Jabra LINK 280
• Jabra LINK 350 OC
• Jabra BIZ 2400 USB
• Jabra GO 6470
• Jabra GO 9470
• Jabra M5390
• Jabra M5390 USB
• Jabra GN9350
• Jabra GN9330
• Jabra GN8120

Polycom devices:

• Polycom Catalina CX200

ZMM devices:

• ZMM Usb Phone

An Update of “Voip By Antisip” has been made. This new release uses the new VP8 codec created by On2 Technologies and acquired by google in February 2010.

For both iOS and android, VP8 provides impressive performance boost in the amsip SDK. It’s a huge step forward for video call quality in “Voip By Antisip” and any other amsip SDK based applications.

Additionnaly, on both iOS and android, libyuv has been added to also improve performance for YUV to RGB conversions as well as resizing operations.

Both libyuv and VP8 are highly optimized for arm and neon platform: both iOS and android get high benefits from those evolutions.

Thanks to those evolutions, we have decided to offer in Voip By Antisip a larger screen rendering by increasing incoming video rendering without breaking ratio! Enjoy the xoom snaphshot below:

VP8 is highly optimised for arm and neon platform. It provides significant performance improvements for iOS and android as well as for desktop (windows, macosx, linux) version.

Check latest version of Voip By Antisip on the android market to see the impressive results!

libyuv is a YUV/RGB image conversion and resizing library highly optimised for arm and neon platform. It provides significant performance improvements for iOS and android.

Check latest version of Voip By Antisip on the android market to see the impressive results!

• G729D at 8Khz (G729D/8000)
• G729E at 8Khz (G729E/8000)
• G729.1 at 16Khz (G7291/16000)

An Update of “Emansip”, our Windows Softphone Demo, has been made. Beside a logo change for the application interface, the latest emansip doesn’t come with new interface feature. However, it uses the latest amsip SDK which has internally a lot of minor changes: interoperability, flexibility and performance!

The upgrade mainly focus on a better support for receiving non standard size. This helps being more interoperable with a few SIP video application.

For French readers!

Chaque abonné de l’opérateur ADSL free en France détient un compte SIP. Ce compte vous permet d’appeler les fixes francais à partir de n’importe quelle application SIP connectée sur Internet: Le cout? 0! C’est inclus dans votre forfait ADSL!

Pour ce faire, sur Android, vous pouvez utiliser l’application “Voip By Antisip”, gratuite, sans pub et à partir de n’importe quelle connection Wi-Fi!

Download Voip By Antisip

Voici une copie d’écran de la configuration nécessaire. Vous devrez insérer 3 informations: le serveur “sip.freephonie.net”, votre numéro de téléphone et votre mot de passe!

Attention, le service freephonie ne fonctionne que sur UDP (contrairement au standard). C’est cruel -sic-! Car même si il reste possible de recevoir des appels sur son mobile, il est fortement déconseillé de laisser tourner une application utilisant SIP sur UDP sur un téléphone Android en tache de fond. Cela consommera votre batterie très rapidement. En effet, un réveil réseau de l’appareil toutes les 15 secondes est nécessaire dans cette configuration! Pour un usage confort, n’oubliez pas de quitter l’application en appuyant sur “Exit” à la fin de vos appels! Ainsi, votre batterie sera préservée!

Pour activer ce compte, chez free:

• rendez vous sur le site https://subscribe.free.fr/login/ et connectez vous a votre compte.
• sélectionnez la rubrique “téléphone”.
• sélectionnez la rubrique “Gestion de mon compte SIP”
• définissez un mot de passe
• vérifiez que l’option “service activé” est bien cochée!
• si vous êtes intéressé, une option vous permet de recevoir les appels sur votre téléphone.

configuration pour freephonie

An Update of “Voip By Antisip” has been made. This new release use the new holographic theme and Action Bar on Android 3.0. The orientation has also been modified to use the “default” orientiation for devices.

On tablet such as xoom, this is really a major step! Enjoy the xoom snaphshot below: