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RE: Transport control API

From: <Markus.Isomaki@nokia.com>
Date: Wed, 11 Sep 2013 10:10:33 +0000
To: <cowwoc@bbs.darktech.org>, <public-webrtc@w3.org>
Message-ID: <E44893DD4E290745BB608EB23FDDB7620A09C534@008-AM1MPN1-041.mgdnok.nokia.com>
Hi,

cowwoc@bbs.darktech.org wrote:
>
>I'd like to bring the following to
> your attention: if you download a large file from DropBox, HTTP will ramp up
> to the peak download rate within 3 seconds.
>

I understand you don't mean "3 seconds" literally, but I find that still a huge oversimplification. How HTTP/TCP download rates behave at the start-up depend at least on the number of TCP connections used, TCP's initial congestion window size (used to be 3 segments, now often more), and the RTT. 3 seconds contains a lot of RTTs on your LAN, but not so many between hosts on different continents.

>      I hope we can all agree that it's unacceptable for it to be taking
> 1-5 minutes to reach the peak rate.

I agree that it should not need to take that long. 

Markus 


> -----Original Message-----
> From: ext cowwoc [mailto:cowwoc@bbs.darktech.org]
> Sent: 11 September, 2013 08:44
> To: public-webrtc@w3.org
> Subject: Re: Transport control API
> 
> 
>      One thing I would like to discuss (unfortunately we ran out of time during
> the call) is whether there is consensus that the current WebRTC
> implementations should ramp up faster.
> 
>      One issue that is consistently brought to bear against the idea of minimum
> bandwidth is network congestion/safety. I'd like to bring the following to
> your attention: if you download a large file from DropBox, HTTP will ramp up
> to the peak download rate within 3 seconds. I don't really need/want a
> "minimum bandwidth". What I really want is WebRTC to ramp up within 3
> seconds.
> 
>      I hope we can all agree that it's unacceptable for it to be taking
> 1-5 minutes to reach the peak rate.
> 
> (In truth, I'd still want min/maxBandwidth fence conditions -- as notifications,
> not hints to the browser -- simply so the application can scale video
> resolution up/down depending on whether it can afford more/less usage).
> 
> Gili
> 
> On 05/09/2013 8:01 AM, Stefan Håkansson LK wrote:
> > On 2013-09-05 13:53, Harald Alvestrand wrote:
> >> On 09/05/2013 09:41 AM, Stefan Håkansson LK wrote:
> >>> Hi all,
> >>>
> >>> I've updated the WiKi page [1] based on what I heard at the teleconf
> >>> September 3rd. Feedback and comments are appreciated.
> >>>
> >>> Note that I'm not claiming this represents consensus, or that I
> >>> correctly understood what people meant at the call. I'm just trying
> >>> to move the discussion forward.
> >>>
> >>> Stefan
> >>>
> >>> [1] www.w3.org/2011/04/webrtc/wiki/Transport_Control
> >>>
> >> I added a few contributions.
> > Thanks. Seems we took away more or less the same from the teleconf.
> >
> >> Remember that this is a wiki - anyone can write on it. (all changes are
> logged, of course).
> > Of course.
> >
> >>
> >>
> >
> 
Received on Wednesday, 11 September 2013 10:12:46 UTC

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