Re: [aqm] Alia Atlas' Yes on draft-ietf-aqm-codel-07: (with COMMENT)

[Jim Gettys <[e-mail]>]

On Thu, Apr 13, 2017 at 4:18 PM, Jim Gettys <[e-mail]> wrote:

>
>
> On Thu, Apr 13, 2017 at 6:34 AM, Mirja Kuehlewind (IETF) <
> [e-mail]> wrote:
>
>> Hi Alia,
>>
>> thanks for your feedback! Just on your first point regarding the status.
>> The working group felt that there was not enough deployment to go directly
>> to standards track and given AQM algorithm don’t need interoperability it
>> was not really important for them to go to standards track right away.
>> However, I leave it to the authors if they are able to add more text on how
>> experimentation should be further performed.
>>
>>
> ​This should be revisited.
>
> fq_codel is the default queue discipline on many/most Linux distributions
> on the planet at this date.
>

​Actually, I take that back.

Codel is present in Linux, but essentially unused; it is there for
experimentation​ (to make it easy for people to compare with fq_codel, PIE,
etc, and to allow the fq_codel spec to reference it.

So Experimental is appropriate for Codel, though explaining why would be
good.  Fq_codel is a different story: it's widely deployed, and there are
multiple implementations (I believe the BSD folks finally got their act
together).
                                                  - Jim

                                                   - Jim
> ​
>
>> Mirja
>>
>>
>>
>> > Am 13.04.2017 um 07:28 schrieb Alia Atlas <[e-mail]>:
>> >
>> > Alia Atlas has entered the following ballot position for
>> > draft-ietf-aqm-codel-07: Yes
>> >
>> > When responding, please keep the subject line intact and reply to all
>> > email addresses included in the To and CC lines. (Feel free to cut this
>> > introductory paragraph, however.)
>> >
>> >
>> > Please refer to https://www.ietf.org/iesg/stat
>> ement/discuss-criteria.html
>> > for more information about IESG DISCUSS and COMMENT positions.
>> >
>> >
>> > The document, along with other ballot positions, can be found here:
>> > https://datatracker.ietf.org/doc/draft-ietf-aqm-codel/
>> >
>> >
>> >
>> > ----------------------------------------------------------------------
>> > COMMENT:
>> > ----------------------------------------------------------------------
>> >
>> > Thank you for a clear and very well written document.  This was well
>> > worth staying up
>> > past 1am to read fully.  I do have one primary comment and a couple
>> minor
>> > points.
>> >
>> > First, the document status is Experimental.   While encouraging
>> > experimentation, the
>> > document doesn't really articulate what the concerns are or how
>> > experimentation might
>> > determine that this should be changed to standards track.  While
>> > regrettably I haven't
>> > personally followed the AQM work, I might assume that some of the issues
>> > to general
>> > applicability might be tied to aspects around the challenges of applying
>> > CoDel to a
>> > system architecture built around WRED AQM and enqueue complexity rather
>> > than dequeue
>> > complexity.  Having a paragraph that gave context in the introduction
>> for
>> > the questions
>> > still to be explored would be helpful.
>> >
>> > a) In Sec 3.4 :  "This property of CoDel has been exploited in
>> >   fq_codel [FQ-CODEL-ID], which hashes on the packet header fields to
>> >   determine a specific bin, or sub-queue, for each five-tuple flow,"
>> >  For the general case of traffic, it would be better to focus on using a
>> > microflow's
>> >  entropy information  - whether that is derived from a 5-tuple, the IPv6
>> > flow label,
>> >  an MPLS Entropy label, etc.  Tying this specifically to the 5-tuple is
>> > not ideal.
>> >  Obviously I missed this for draft-ietf-aqm-fq-codel-06 - but even a
>> > slight rephrasing
>> > to "for each microflow, identifiable via five-tuple hash, src/dest +
>> IPv6
>> > flow label, or
>> > other entropy information" would encourage better understanding of
>> > micro-flow identification.
>> > Of course, this is just a comment - so do with it what you will.
>> >
>> > b) (Nit) In Sec 5.1: " We use this insight in the pseudo-code for CoDel
>> > later in the draft."
>> >  The pseudo-code is actually earlier in the draft.  Also
>> > s/draft/document for publication.
>> >
>> >
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