Subject: [PMOL] draft-ietf-pmol-metrics-framework-08.txt posted

From: Benoit Claise <[email-masked]>
Date: Fri, 28 Jan 2011 11:45:24 +0100

Dear all,

Now that the WG Last Call is over, I submitted a new version of the PMOL 
framework.
http://www.ietf.org/id/draft-ietf-pmol-metrics-framework-08.txt

It includes the feedback from: sec-dir, gen-art, rtg-dir, and ops-dir

Regards, Benoit.

---

From: Al Morton <[email-masked]>
Date: Fri, 28 Jan 2011 15:56:17 -0500

That's IETF Last Call, n'est pas?

At 05:45 AM 1/28/2011, Benoit Claise wrote:
>Dear all,
>
>Now that the WG Last Call is over, I submitted a new version of the 
>PMOL framework.
>_______________________________________________
>PMOL mailing list
>[email-masked]
>https://www.ietf.org/mailman/listinfo/pmol

---

From: Benoit Claise <[email-masked]>
Date: Sat, 29 Jan 2011 15:04:17 +0100

Al,

Yes indeed. My mistake.

Regards, Benoit

---

From: Vinayak Hegde <[email-masked]>
Date: Sun, 30 Jan 2011 00:20:29 +0530

Hi Benoit,

The RFC certainly looks good and does covers a lot of ground. I would
like to add some more information to the RFC. My comments follow:

In section 2.2

You might want to add that we might need to invite experts based on
the protocol metrics that RFC intends to address (for example HTTP,
SIP, SCTP, SFTP etc). You will need to invite experts to address the
nuances of the each protocol which can influence the metrics.

In Section 5.1

A couple more additions here - Two more factors that can cause
variation (mostly for live traffic) is

1. Sampling criteria
Sampling can be done randomly (probabilistic) or you can look at every
nth connection or every nth packet. The sampling criteria might
introduce some bias in the measurements.

2. Period (and duration) of measurement
Some live traffic can have patterns eg. measurement of FTP/ HTTP
latency during 24 hours. The traffic is generally high during the
mid-day and low at the middle of the night. There is similar
variations during the week depending on the type of traffic being
measured. Furthermore economic incentives such as pricing plans (no
cap accounting during night for example) can have bearing on the final
measurement results. Care needs to be taken to account for a complete
"pattern cycle" for such measurements.

In section 5.3.1

Another type of metric that can be useful is when the time spans might
be overlapping. Many such metrics are those that are based on moving
windows. A good example is streaming protocols / applications that
rely on buffering (where you need to look at moving windows to measure
QoE). Such measurements can be useful to model the QoE when there is
burst loss. Since all packets are not created equal the same amount of
packets can have different impacts when they occur in a pattern within
a moving window (such as a glitch in video or clicks/gaps in audio).

In Section 5.4.2

(iii) Method of Measurement or Calculation
Some methods of calculation might require discarding some data
collected (due to outliers) so as to make the measurement parameters
meaningful. Example is burstable billing which is pretty common in
ISPs (see http://en.wikipedia.org/wiki/Burstable_billing for more
details). In this after sorting the 5-min samples, the top 5
percentile data is discarded.

Please add -

(vii) Characteristics of underlying traffic

Characteristics of underlying traffic on which measurement is done is
important as noted above (due to difference in traffic patterns). Also
in video/audio some packets might be more important as compared to
others based on the codec and buffering pattern of the application.

Regards
Vinayak

---

From: Al Morton <[email-masked]>
Date: Sun, 30 Jan 2011 09:10:04 -0500

Hi Vin,

You raise some interesting informational points.

Unfortunately, both the Working Group and IETF-wide
Last Calls ended some time ago, and Benoit has published the
version that the IESG will consider at their next meeting.

Perhaps Benoit can see if there is any commonality with
IESG comments, and incorporate some of your thoughts
if possible.

regards,
Al

At 01:50 PM 1/29/2011, Vinayak Hegde wrote:
>...<stuff deleted>...