Re: [rtcweb] Should we reference the pause/resume I-D?

"Charles Eckel (eckelcu)" <> Thu, 20 March 2014 20:25 UTC

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From: "Charles Eckel (eckelcu)" <>
To: Roni Even <>, 'Justin Uberti' <>, 'Bernard Aboba' <>
Thread-Topic: [rtcweb] Should we reference the pause/resume I-D?
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Date: Thu, 20 Mar 2014 20:25:05 +0000
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Subject: Re: [rtcweb] Should we reference the pause/resume I-D?
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Caveats to be aware of with the tmmbr=0 approach include:

  *   tmmbr=0 implies pause, but it is indistinguishable for tmmbr being set to 0 for other reasons
  *   knowledge of an appropriate value to set for resume is not always available at the RTCP layer (implementation dependent)
  *   theoretically not appropriate to jump directly back to tmmbr=<value prior to pause> even when known

Despite these caveats, I agree with Roni that using tmmbr=0 for pause has worked relatively well in enterprise SIP deployments.


From: Roni Even <<>>
Date: Thursday, March 20, 2014 at 4:41 AM
To: Justin Uberti <<>>, 'Bernard Aboba' <<>>
Cc: "<>" <<>>
Subject: Re: [rtcweb] Should we reference the pause/resume I-D?

The pause and resume has the tmmbr=0 option based on RFC5104 (No IPR in the data base for RFC 5104;  . this works well for point to point case.

From: rtcweb [] On Behalf Of Justin Uberti
Sent: 12 March, 2014 10:56 PM
To: Bernard Aboba
Subject: Re: [rtcweb] Should we reference the pause/resume I-D?

Agreed. Aren't there also patent declarations against this doc from multiple holders?

While SDP will likely be removed from the API in the future, the replacement would be a app-specific message sent over websockets, which seems like it would work just fine.

On Wed, Mar 12, 2014 at 12:50 PM, Bernard Aboba <<>> wrote:
While I do like the pause/resume draft, having core RTCWEB WG documents (such as RTP Usage) depend on it seems like a bit of a stretch. After all, the document was only adopted last week, and it is a rare IETF WG document that can go from a -00 WG draft to publication as an RFC in under a year.

On Wed, Mar 12, 2014 at 11:01 AM, Stefan Håkansson LK <<>> wrote:

at the IETF last week there was consensus in the AVTEXT WG meeting to
adopt the pause/resume draft [1] as a WG draft.

In rtcweb/webrtc we're have the situation that we're discussing so
called "doo-hickeys" as an API surface where the web app (amongst other
things) can pause and resume the sending of a track. This can
be signaled with the direction attribute and a SDP O/A exchange (and the
app pausing/resuming sending of a track would presumably lead to a
"negotiationneeded" event being fired).

But I think we should in addition require the browser to signal it
according to one of the methods in [1] (e.g. TMMBN = 0), and also
understand that signaling (a browser receiving TMMBN = 0 must know that
the other end-point will pause sending).

My argument is that we know that many dislike SDP in rtcweb, and a
likely development is that it will be removed in a later version. My
speculation is that signaling as outlined in [1] will then be used for
pause/resume. If we support this from the beginning earlier
implementations could more easily interop with those later versions.



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