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

["Xiaoqing Zhu (xiaoqzhu)" <[e-mail]>]

Hi, 

I would like to provide my input on this discussion.  

My understanding is that the test case draft specifies scenarios over which we would like to evaluate candidate algorithms (oh well, stating the obvious.) As such, Sec 5.4 (Competing Flows with Same RMCAT Algorithm) is a good place to add one flavor/variation of the test set up, whereby all senders share the same physical node so that one can test how a coupled CC solution works.  

I don't see why the test case draft need to say anything additional (e.g., whether a proposed CC solution should be combined with which flavor of the candidate algorithm) beyond describing that sub-test case. 

Thanks,
Xiaoqing



________________________________________
From: rmcat <[e-mail]> on behalf of Mirja Kühlewind <[e-mail]>
Sent: Wednesday, February 24, 2016 3:06 AM
To: Zaheduzzaman Sarker
Cc: [e-mail]; Michael Welzl
Subject: Re: [rmcat] test cases for coupled cc [was: Re: Review of draft-ietf-rmcat-eval-test-02]

Hi Zahed,

I agree with Michael. My view is here that we need to evaluate each
combination of a certain scheme to couple things using a certain congestion
control algorithm separately. That means, if someone proposes a new (generic)
scheme for coupling, we as a group would only advise to use this scheme with
a certain cc algorithm if we have seen results for this specific combination.
Does this make sense to you?

I hope this also reflects the view of the wg. If not, please let us now and
we would need to discuss this again.

Mirja


On 16.02.2016 17:42, Michael Welzl wrote:
> Hi,
>
> My 2 cents about one bit here, cutting away the rest:
>
>
>> On 16. feb. 2016, at 02.14, Zaheduzzaman Sarker <[e-mail]> wrote:
>> (..)
>> On 02/10/2016 03:36 PM, Safiqul Islam wrote:
> (..)
>
>
>>> 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?
>> I dont think this document to referent to any candidate solution.
>>
>> I think the test cases should be defined so that one can evaluate other alternatives if there is any. Now, if there is more than one coupled CC solution and the candidate algorithms perform differently with different solution, how that will help us to evaluate coupled Congestion control algorithms. How does the WG plans to solve such situation?
>
> The sentence Safiqul proposed mentions the coupled-cc draft as an example - not more, not less. Remove it if you want, and nothing has changed: this isn’t about evaluating coupled CC. algorithms, it’s about evaluating how congestion control algorithms work when they are combined with a method to couple them. It’s not mandatory either - but if you want to test how e.g. SCReAM operates when coupled, these test cases probable make sense. That’s all this says.
>
> Cheers,
> Michael
>