Re: [rmcat] test cases for coupled cc [was: Re: Review of draft-ietf-rmcat-eval-test-02]

[Safiqul Islam <[e-mail]>]

HI Zahed, Hi Mirja,

Please see inline

/Safiqul


On 10. feb. 2016, at 10.24, Zaheduzzaman Sarker <[e-mail]<mailto:[e-mail]>> wrote:

Hi Mirja,

please see inline....

On 2016-02-09 15:51, Mirja Kühlewind wrote:

The test cases in the draft were designed for end-point adaptation
algorithm without coupled congestion control in mind i.e. no need
for shared bottleneck detection and flow priority. In the last IETF
meeting we talked about the possibility of extending the test cases
to include coupled congestion control algorithm.

I believe we decided already at the last meeting that we need to
adapt this draft to include uses cases for coupled congestion (and
that’s why we asked Safiqul to propose some).

That is what I can also recall but didn't see anything in the meeting
minutes so was not sure what we agreed on. May be missed it in the meeting minutes.



Now if we extend the test cases then I don't think only adding the
two proposed test cases will be sufficient.

Yes, that might be true but adding these use cases below would
probably be a good starting point.

If I understand shafiqul's last mail, it is fine with only having test results with priority for 5.4 test case.

For simplicity, I suggested to use only test case 5.4, but I am not against using other cases.
I can add some recommendations for other cases too.



We will need to identify all the test cases those are suitable for
running with coupled congestion control.

Not sure, if you only have one flow that test case is simply not
suitable and that’s fine.
Yes, that is one identification criteria. But may be we dont need results for all the test cases who has more than one flow. see my previous comment.

+1



Like 5.2 can be run with priority per flow. By doing this we can
mention (in each test case or in one place in the document) that
one can run tests with flow priority and perhaps give some means to
evaluate the available capacity distribution with some equation
like the one mentioned here in the proposed test case 6.3.

Yes.

However, then this document also needs to include description for
shared bottleneck detection.

Why?
Bcos I dont think the document now even mention "shared bottleneck" and to me coupled congestion control does not make sense without shared bottleneck.

The document covers the basic scenarios where flows share a common bottleneck.  We can simply add a line saying “these additional coupled-cc test-cases are used for flows sharing a bottleneck”.


In the simplest form, we can perhaps assume that the identified
test cases have single bottleneck point.

Yes.


I think we need to discuss what is best possible way to extend the
test cases if we agreed to do that.

As I said I think we agreed already. Please following with Safiqul on
this!


But before that I would like to know if the WG is OK with extending
the test cases for coupled congestion control.

Any further feedback on this from the group is of course welcome!
Please speak up now!


And will it be a compulsory (candidate algorithms MUST present
results) or optional (candidate algorithms MAY present results)
part of the test case.

I guess only candidates that use coupled cc..?

hmm...

I am a bit confused now. Are we talking about test case(s) to evaluate the Coupled CC or the use of Coupled CC in the candidate CC?


Without making it compulsory, I suggested to add these in the other cases. We can perhaps say:

“When flows share a common bottleneck, combining their congestion controllers can be beneficial.
These additional test cases can be used to evaluate a congestion control mechanism when using a method to couple flows, such as [I-D.ietf-rmcat-coupled-cc]."

Does this put it better?

Regards,
Safiqul


BR

--
Zahed

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ANM ZAHEDUZZAMAN SARKER


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