Re: [rtcweb] Asking TLS for help with media isolation

Martin Thomson <> Tue, 08 April 2014 18:24 UTC

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Date: Tue, 08 Apr 2014 11:24:03 -0700
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From: Martin Thomson <>
To: Bernard Aboba <>
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Subject: Re: [rtcweb] Asking TLS for help with media isolation
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On 8 April 2014 09:50, Bernard Aboba <> wrote:
> [BA] I'm not sure that the concept of "isolation" makes sense for those
> intermediaries (or to voicemail or an audio/video conference, for that
> matter).   While in a point-to-point call it might be useful, in a
> conference the whole point is to have audio/video sent to multiple parties,
> and recording is commonplace.  The problem is that from a protocol point of
> view the cases are not easily distinguishable -- and so if the browser
> insists on "isolation" then one wonders what will happen if the conference
> bridge/video MCU/voicemail system refuses to negotiate it.   Refusing to
> send media would not be a desirable outcome.

I think that for this, it's perfectly reasonable to use identity, but
not stream isolation.  With isolation, if the peer does not agree to
comply, then the session fails to complete.

The authenticated party here is an MCU (or bridge, or voicemail,
etc...).  Rather than sending to "", media is
sent to "".  Is it reasonable for that MCU to forward
media to other, unspecified entities?  Clearly it can, but should it?

(Not having thought it through completely, a voicemail box could
conceivably work.  I think that I'd want to use a different identity
for it though.)