Re: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and bottleneck queue size

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

Hi Ingemar,


I encountered the same problem when running that test case. Then I noticed a discrepancy between the specification in the eval-test draft and the eval-criteria draft (https://tools.ietf.org/html/draft-ietf-rmcat-eval-criteria-05#section-6.1?)


In Section 6.1, the model for short TCP specifies 30 concurrent connections with 30-50KB each in data size.


So, for the moment, I am taking the "min" of both descriptions.  I am testing TC5.7 with 10 short TCP flows, 2 of them start in the ON state while rest of the 8 flows start in an OFF states (according to eval-test).  Each download attempt picks a data size ranging between 30-50KB (according to eval-criteria). Note that each short TCP connection incurs multiple downloads as it cycles through ON/OFF states for the entire duration of the simulation.


As co-author of the eval-test draft, I would like to propose this revised test set up for TC5.7, and corresponding text changes in the eval-criteria draft.  Would of course need input from other co-authors of the two drafts. Alternative suggestions are welcome too.


Thanks,

Xiaoqing




________________________________
From: rmcat <[e-mail]> on behalf of Ingemar Johansson S <[e-mail]>
Sent: Tuesday, June 28, 2016 3:47 PM
To: Zaheduzzaman Sarker; [e-mail]
Subject: Re: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and bottleneck queue size

OK, then I get it, thanks.
Stumbled on another question, though.

When I run TC 5.7 (many small TCP flows), it seems like the TCP pressure becomes quite high. If I run completely without RMCAT flow the 2Mbps link gets almost fully saturated 100% of the time.
The settings I use are
Linux TCP with Cubic
10 FTP clients
  100kB-1000kB file size (uniform distribution)
  Idle time between reads, 10s mean, exponentially distributed.
Have I misunderstood the description for TC5.7 ?


/Ingemar

From: Zaheduzzaman Sarker
Sent: den 28 juni 2016 22:28
To: Ingemar Johansson S <[e-mail]>; rmcat WG ([e-mail]) <[e-mail]>
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and bottleneck queue size

Please see inline below.

BR

Zahed

From: rmcat [mailto:[e-mail]] On Behalf Of Ingemar Johansson S
Sent: den 28 juni 2016 18:13
To: rmcat WG ([e-mail]<mailto:[e-mail]>) <[e-mail]<mailto:[e-mail]>>
Subject: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and bottleneck queue size

Hi

The text in section 4.2 in draft-ietf-rmcat-eval-test-03 confuses me somewhat
It mentions a bottleneck queue size of 300ms, given that the capacity changes this means that the queue size in bytes of a drop tail queue should change as well or ?
[Zaheduzzaman Sarker] No.
Or is the intention that one use the Reference bottleneck capacity to compute a queue size
With a ref bottleneck capacity of 1Mbps
[Zaheduzzaman Sarker] yes
and 300ms queue size that would then mean
0.300*1e6 = 300000bits ?

/Ingemar

==================================
Ingemar Johansson  M.Sc.
Master Researcher

Ericsson AB
Wireless Access Networks
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