[Cake] COBALT implementation in ns-3 with results under different traffic scenarios

Jendaipou Palmei jendaipoupalmei at gmail.com
Wed Dec 5 07:23:40 EST 2018


Hello Dave and Jonathan,

Thanks for the feedback!

We have uploaded the corresponding graphs for reference CoDel.

Link: https://github.com/Daipu/COBALT/wiki/Drop-Count-Graph

We have also plotted the instantaneous throughput for all flows in Light
traffic scenario for COBALT and CoDel.
These graphs are plotted for packet size with 1000 bytes and 1500 bytes.

Link: https://github.com/Daipu/COBALT/wiki/Throughput-for-Separate-Flow

We're currently working on the following:

1. plots for the actual number of marks/drops per time interval for COBALT,
CoDel, and PIE.
2. zoomed in plots on small time intervals to show the dynamic behavior of
the algorithm.
3. a file showing the timestamp of each drop.

About collaborating for writing a paper on this work: we'd be glad to do so
:) thanks for your guidance and help!

Thanks and regards
Jendaipou Palmei
Shefali Gupta

On Tue, Dec 4, 2018 at 8:51 PM Dave Taht <dave.taht at gmail.com> wrote:

> On Tue, Dec 4, 2018 at 7:02 AM Jonathan Morton <chromatix99 at gmail.com>
> wrote:
> >
> > > On 4 Dec, 2018, at 12:31 pm, Jendaipou Palmei <
> jendaipoupalmei at gmail.com> wrote:
> > >
> > > We have uploaded the plots for the 'count' variable of COBALT (with a
> segment size of 1500 and 1000 bytes).
> > >
> > > Link: https://github.com/Daipu/COBALT/wiki/Cobalt-Drop-Count
> > >
> > > We have not yet implemented ECN feature in COBALT, so packets are
> currently dropped instead of being marked.
> > >
> > > Are these the plots that you were referring to?
> >
> > More-or-less, yes, though these actually show an internal state variable
> of the Codel algorithm rather than the actual number of marks/drops per
> time interval.  I was hoping to see similar graphs for the reference-Codel
> and PIE runs, since we can gain more insight from that, and PIE doesn't
> have an internal "count" variable that corresponds with Codel.
> Nevertheless, the view into "count" behaviour is interesting in itself, and
> I'd like to see the corresponding graphs from reference Codel.
> >
> > An artefact visible in these graphs is an apparent lack of sampling
> while not in the dropping state.  Thus you seem to have a gradual ramp from
> 0 to 1 count over the several seconds interval between activations, though
> in fact the variable is discrete.  It would be better to show that
> transition more precisely.
> >
> > For study, it is also often helpful to zoom in on small time intervals
> to see the dynamic behaviour of the algorithm, particularly during the
> transition from slow-start to steady-state, where there is seemingly a big
> difference between reference Codel and COBALT.
>
> I'm loving the slow start result.
>
> >
> > Another interesting graph to produce for each algorithm and traffic type
> is the instantaneous throughput of each flow.  This offers insight into the
> relative fairness of each algorithm, and might help to explain the anomaly
> seen with 1000-byte packets and COBALT.  Usually this graph also reveals,
> through the shape of each throughput curve, which CC algorithm is in use -
> currently I'm guessing NewReno.  CUBIC and CTCP, which are also in common
> use, would behave differently.
>
> a file showing the timestamp of each drop would be easier to post process.
>
> >
> >  - Jonathan Morton
> >
>
>
> --
>
> Dave Täht
> CTO, TekLibre, LLC
> http://www.teklibre.com
> Tel: 1-831-205-9740
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/cake/attachments/20181205/27dc3acb/attachment.html>


More information about the Cake mailing list