[R-C] LEDBAT - introductions?

[Fu Jiantao]

Hi Harald,

   I think there's some misunderstanding here.

   1.  ledbat is using qeueing delay, not the base rtt, the queuing delay
is relative_owd - relative_base_owd, and clock skew is removed.

   2. I mentioned ledbat here for i think there's simpler way to get the
queuing delay as a hint for congestion, and can be used for give estimation
of bandwidth.


Thanks
Jeromy

2012/4/6 Harald Alvestrand <harald at alvestrand.no>

> On 04/06/2012 01:45 AM, Matt Mathis wrote:
>
>> There is one especially useful design point to extract here.....
>>
>> I believe that by default ledbat has a 50mS set point.  That is, it
>> regulates its rate/window size by sensing if the one way queue time seems
>> to be above or below 50mS.
>>
> That is - 50 ms more than the baseline (lowest observed) RTT?
> 50 ms absolute would make no sense, since intercontinental conferencing
> has a longer baseline RTT.
>
>
>> Would this be acceptable for RTCweb, or would it be necessary to choose
>> some other set point?
>>
> I generally don't like set-points, since they tend to make behaviour
> converge on the set-point. Sliding scales like the Kalmann filter of
> Stefan's proposal make more sense to me.
>
> That said, 50 ms seems a little on the high side, given that our total RTT
> budget is being attacked from all sorts of directions, but not
> order-of-magnitude wrong.
>
>
> ______________________________**_________________
> Rtp-congestion mailing list
> Rtp-congestion at alvestrand.no
> http://www.alvestrand.no/**mailman/listinfo/rtp-**congestion<http://www.alvestrand.no/mailman/listinfo/rtp-congestion>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.alvestrand.no/pipermail/rtp-congestion/attachments/20120406/3b80204c/attachment.html>