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

From: Ingemar Johansson S <[email-masked]>
Date: Tue, 28 Jun 2016 16:13:28 +0000

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 ?

Or is the intention that one use the Reference bottleneck capacity to
compute a queue size 

With a ref bottleneck capacity of 1Mbps and 300ms queue size that would then
mean 

0.300*1e6 = 300000bits ?

/Ingemar

==================================

Ingemar Johansson  M.Sc. 

Master Researcher

Ericsson AB

Wireless Access Networks

Labratoriegränd 11

971 28, Luleå, Sweden

Phone +46-1071 43042

SMS/MMS +46-73 078 3289

 <mailto:[email-masked]> [email-masked]

www.ericsson.com

    Real knowledge is to know the 

       extent of one's ignorance

                 Confucius

==================================

---

From: Zaheduzzaman Sarker <[email-masked]>
Date: Tue, 28 Jun 2016 20:27:57 +0000

Please see inline below.

BR

Zahed

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

Hi

[Zaheduzzaman Sarker] No.

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

Labratoriegränd 11

971 28, Luleå, Sweden

Phone +46-1071 43042

SMS/MMS +46-73 078 3289

www.ericsson.com

                 Confucius

---

From: Ingemar Johansson S <[email-masked]>
Date: Tue, 28 Jun 2016 20:47:54 +0000

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 <[email-masked]>; rmcat WG
([email-masked]) <[email-masked]>
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and
bottleneck queue size

Please see inline below.

BR

Zahed

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

Hi

0.300*1e6 = 300000bits ?

/Ingemar

Ingemar Johansson  M.Sc. 

Master Researcher

Ericsson AB

Wireless Access Networks

Labratoriegränd 11

971 28, Luleå, Sweden

Phone +46-1071 43042

SMS/MMS +46-73 078 3289

www.ericsson.com

                 Confucius

---

From: "Xiaoqing Zhu (xiaoqzhu)" <[email-masked]>
Date: Tue, 28 Jun 2016 21:01:14 +0000

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

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 <[email-masked]>; rmcat WG ([email-masked]) <[email-masked]>
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and bottleneck queue size

Please see inline below.

BR

Zahed

From: rmcat [mailto:[email-masked]] On Behalf Of Ingemar Johansson S
Sent: den 28 juni 2016 18:13
To: rmcat WG ([email-masked]<mailto:[email-masked]>) <[email-masked]<mailto:[email-masked]>>
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

Ericsson AB
Wireless Access Networks
Labratoriegränd 11
971 28, Luleå, Sweden
Phone +46-1071 43042
SMS/MMS +46-73 078 3289
[email-masked]<mailto:[email-masked]>
www.ericsson.com

---

From: Zaheduzzaman Sarker <[email-masked]>
Date: Tue, 28 Jun 2016 22:15:08 +0000

Hi,

Not sure I understand the confusion.

If there is no other traffic on the path except the TCP traffic the path
capacity is supposed to filled up by the TCP traffic.

By the way, the short flows are supposed to me modeled according to
https://tools.ietf.org/html/draft-ietf-rmcat-eval-criteria-04#section-6.1

May be we should remove the test specific information section for the
eval-test draft.

BR

Zahed

From: Ingemar Johansson S 
Sent: den 28 juni 2016 22:48
To: Zaheduzzaman Sarker <[email-masked]>; [email-masked]
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and
bottleneck queue size

The settings I use are

Linux TCP with Cubic

10 FTP clients 

 

/Ingemar

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

Please see inline below.

BR

Zahed

Hi

0.300*1e6 = 300000bits ?

/Ingemar

Ingemar Johansson  M.Sc. 

Master Researcher

Ericsson AB

Wireless Access Networks

Labratoriegränd 11

971 28, Luleå, Sweden

Phone +46-1071 43042

SMS/MMS +46-73 078 3289

www.ericsson.com

                 Confucius

---

From: Ingemar Johansson S <[email-masked]>
Date: Wed, 29 Jun 2016 05:22:48 +0000

The problem I see is that with the original settings in section 5.7 in
draft-ietf-rmcat-eval-test-03 you have a number of TCP connections (ranging
from 1 to 10, depending on the randomized settings) that continuously
slowstart into a quite low bitrate bottleneck (only 2Mbps). What you get is
a very bursty traffic pattern that will hit a delay sensitive congestion
control quite badly with very low media bitrate as a result. 

Changing to an object size distribution between 30 and 50kbps gives bursty
transmission too but that is still manageable as the TCP flows do not
saturate the link.

/Ingemar

From: Zaheduzzaman Sarker 
Sent: den 29 juni 2016 00:15
To: Ingemar Johansson S <[email-masked]>; [email-masked]
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and
bottleneck queue size

Hi,

 

BR

Zahed

From: Ingemar Johansson S 
Sent: den 28 juni 2016 22:48
To: Zaheduzzaman Sarker <[email-masked]
<mailto:[email-masked]> >; [email-masked]
<mailto:[email-masked]> 
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and
bottleneck queue size

The settings I use are

Linux TCP with Cubic

10 FTP clients 

 

/Ingemar

Please see inline below.

BR

Zahed

Hi

0.300*1e6 = 300000bits ?

/Ingemar

Ingemar Johansson  M.Sc. 

Master Researcher

Ericsson AB

Wireless Access Networks

Labratoriegränd 11

971 28, Luleå, Sweden

Phone +46-1071 43042

SMS/MMS +46-73 078 3289

www.ericsson.com

                 Confucius

---

From: Zaheduzzaman Sarker <[email-masked]>
Date: Wed, 29 Jun 2016 10:02:25 +0000

Hi Ingemar,

If you have any suggestion on the TCP model and if you can show some results
on the effect of different TCP short flow modeling (the one in eval-test
draft, the one in eval-criteria draft and your suggestion) at the IETF96
meeting that will be really great. We can discuss and agree on changing the
model.

The current convention is that all the modeling goes to the eval-criteria
draft hence we should remove the test specific information from section 5.7
(I think it is there by mistake).

Thanks for finding the discrepancies.

BR

Zahed

From: Ingemar Johansson S 
Sent: den 29 juni 2016 07:23
To: Zaheduzzaman Sarker <[email-masked]>; [email-masked]
Subject: RE: [rmcat] Question on draft-ietf-rmcat-eval-test-03 and
bottleneck queue size

/Ingemar

<mailto:[email-masked]> >; [email-masked]

Hi,

 

BR

Zahed

The settings I use are

Linux TCP with Cubic

10 FTP clients 

 

/Ingemar

Please see inline below.

BR

Zahed

Hi

0.300*1e6 = 300000bits ?

/Ingemar

Ingemar Johansson  M.Sc. 

Master Researcher

Ericsson AB

Wireless Access Networks

Labratoriegränd 11

971 28, Luleå, Sweden

Phone +46-1071 43042

SMS/MMS +46-73 078 3289

www.ericsson.com

                 Confucius