Re: [rtcweb] media rollback and glare

"Rauschenbach, Uwe (NSN - DE/Munich)" <> Thu, 08 August 2013 14:51 UTC

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From: "Rauschenbach, Uwe (NSN - DE/Munich)" <>
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Thread-Topic: [rtcweb] media rollback and glare
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Date: Thu, 08 Aug 2013 14:51:00 +0000
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Subject: Re: [rtcweb] media rollback and glare
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In the Open Mobile Alliance, a REST API is being defined, intended to be exposed by a gateway that offers WebRTC access to IMS (or even PSTN). 
For that work, it is also necessary to understand how rollback will work in the PeerConnection API.
Kind regards,
Uwe Rauschenbach

Dr. Uwe Rauschenbach
Senior Specialist 
NSN, Technology & Innovation
St.-Martin-Str. 76, D-81541 Munich, Germany 
Tel.: +49 89 5159 29751
Mobile: +49 173 3083573 

Nokia Siemens Networks Management International GmbH 
Geschäftsleitung / Board of Directors: Andreas Sauer, Ralf Dietzel 
Sitz der Gesellschaft: München / Registered office: Munich 
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From: [] On Behalf Of ext Andrea Dixon
Sent: Thursday, August 08, 2013 12:17 PM
Subject: [rtcweb] media rollback and glare

The Webrtc spec states:
"This API changes the local media state. In order to successfully handle scenarios where the application wants to offer to change from one media format to a different, incompatible format, the RTCPeerConnection must be able to simultaneously support use of both the old and new local descriptions (e.g. support codecs that exist in both descriptions) until a final answer is received, at which point the RTCPeerConnection can fully adopt the new local description, or roll back to the old description if the remote side denied the change.
Issue 8
ISSUE: how to indicate to roll back?"
When will rollback be added to webrtc? Is it imminent? We need it to resolve glare scenarios where both peers renegotiate at the same time. Or is there another way of resolving glare in webrtc? This is becoming a pressing concern.
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