[R-C] Fairness of RRTCC and TCP

[Varun Singh]

Hi Piers,

comments inline.
On Thu, Aug 2, 2012 at 9:14 PM, Piers O'Hanlon <p.ohanlon at gmail.com> wrote:
> Hi Varun,
>
> This looks interesting - it would be nice to see self-fairness performance as well. What model did you use for the

The second set of experiments 2 RTP and TCP, which is not exactly
evaluating for self fairness but the last two graphs show the two RTP
flows stacked on top of one another.

> codec in ns2 (EvalVid or mpeg_traffic or other) ?
>

I dont use either but, I'd have to use EvalVid_RA for this because
AFAIK EvalVid does only fixed rate. On the other hand, we have an
implementation which connects ns2 to a real codec over IPC, but the
simulations take a lot of time and therefore preferred to do just
packet simulations in the first iteration.

In these simulations, I simplify and use equal sized frames instead of
a group of pictures (I would have to run more simulations to vary GoP
and measure its impact and didn't want to pick a wrong GoP for these
preliminary results).

> I (and probably others) would be interested to have access to the ns2 RRTCC implementation - would it possible to release the source code? (Though I'd be surprised if Google haven't already implemented it in ns2/3 already as well ...)

The code is currently still work in progress as I am also
experimenting with other types of congestion indicators/algorithms
(and would need some more time for cleanup) but, I have been using
http://code.google.com/p/webrtc/source/browse/#svn%2Ftrunk%2Fsrc%2Fmodules%2Fremote_bitrate_estimator
as a guideline for the implementation.

Regards,
Varun

>
> Thanks,
>
> Piers
>
>
>
> On 2 Aug 2012, at 08:47, Varun Singh wrote:
>
>> Hi,
>>
>> Following up on the discussion of fairness between interactive
>> real-time flows and TCP.
>> I've implemented the RRTCC in NS-2 and attached within are the
>> preliminary results.
>>
>> The scenarios that we simulated are:
>> 1. RRTCC flow shares a bottleneck with short TCP.
>> 2. two RRTCC flows share a bottleneck with with short TCP flows.
>>
>> The short TCP flows are modelled as on/off flows. The size of the data
>> is obtained from a uniform distribution between 100KB and 1.5MB, and
>> the idle periods are obtained from an exponential distribution with
>> the mean as 10.
>>
>> The results are available as a short presentation at: http://bit.ly/rrtcc-tcp
>>
>> I would appreciate any comments and/or feedback.
>>
>> Cheers,
>> Varun
>> _______________________________________________
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>> Rtp-congestion at alvestrand.no
>> http://www.alvestrand.no/mailman/listinfo/rtp-congestion
>



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