Maybe we should split the WiFi CC question in two. One is about solutions to the problem, i.e., how exactly do we implement congestion control and data scheduling algorithms that achieve desired results when various applications compete for Wi-Fi access. The second is, what should RFC5053bis say about that.

I have ideas about the Wi-Fi problem that may or may not be useful. But when it comes to RFC5033bis, the problem is obvious. The impetus of RFC5033 was, "don't break the Internet by fielding CC algorithms that send too much data." It is almost entirely about bandwidth and capacity, and very little about latency, or the impact that a connection's traffic will have on latency experienced by other connections. That's something that I believe should change with RFC 5033bis.

My first idea was to tie this to bufferbloat (see: https://github.com/rscheff/rfc5033bis/issues/8), because "filling buffers and queues to capacity" is one of the worse ways a CC algorithm can increase latency for competing apps. But there are other ways, as Matt points out for Wi-Fi.

-- Christian Huitema

On 2/19/2023 6:10 AM, Matt Mathis wrote:
Dave, I was referring to the underlying technical problems for WiFi CC and competition between video conferencing, gaming and bulk data.  Are you convinced that there exist deployable solutions that would be viewed as correct by all parties?  I am not.

To the extent that solutions exist we can shape the process/WG scope to encompass it.  I am not at all worried about that part of the problem, even after the fact.

I think I have a pretty good understanding of WiFi vs CC, and the fundamental tradeoff between transport causing backlog to facilitate batching MACs vs fully paced flows that never inflict unnecessary jitter on other flows.

The other problem has been technically solved many times over, except none of the solutions have been deployed widely enough.  New solutions in this space actually make the deployment problem worse.

Thanks,
--MM--
Evil is defined by mortals who think they know "The Truth" and use force to apply it to others.


On Fri, Feb 17, 2023 at 12:16 PM Dave Taht <[email protected] <mailto:[email protected]>> wrote:

    On Fri, Feb 17, 2023 at 10:43 AM Matt Mathis
    <[email protected]
    <mailto:[email protected]>> wrote:
     >
     > Dave, I'd be curious to know what you think is the proper shape
    for either of the problems that you pose.  Both have deep
    ambiguities/conflicts in the definition of correct, in the sense
    that solutions that would be considered optimal by some audiences
    call for behaviors that would be considered anti-optimal by others.

    I am sorry, Matt, are you looking for me to wordsmith things relative
    to updating RFC5033, or issues of the draft "congress" charter? If the
    former...

    :before:

    The IETF's standard congestion control schemes have been widely shown
         to be inadequate for various environments (e.g., high-speed
         networks).

    :after:

    The IETF's standard congestion control schemes have been widely shown
    to be inadequate for various environments (e.g., high-speed networks,
    wireless technologies such as 3GPP and WiFi, long distance satellite
    links)  and also in conflict with the needed, more isochronous,
    behaviors of VOIP, gaming, and videoconferencing traffic.

    ...

    Would be a start, I suppose. I am perhaps well known for my fierce
    desire to make human interactive traffic as near zero latency and
    jitter as possible, all the time. I am not sure how this could be
    considered sub-optimal except by AIs. My ideal internet would have no
    more than 2ms jitter in it,
    and the parameters of all the probing techniques fit within that.

    ...

    What I observe today in high speed networks is most TCP flows never
    getting out of slow start, with folk building request/response
    protocols that complete in a single round trip, with IW256 (or
    higher), FQ'd at the switch, and paced by the host. Is this what
    others are seeing?

    To skip to the end of RFC5033, it seemingly depends on work in
    progress from 2008, the last draft of that, is here:

    https://datatracker.ietf.org/doc/html/draft-irtf-tmrg-tools
    <https://datatracker.ietf.org/doc/html/draft-irtf-tmrg-tools>

    It is a very good read. Was there a successor?

    As for the middle...

     >
     > Thanks,
     > --MM--
     > Evil is defined by mortals who think they know "The Truth" and
    use force to apply it to others.
     >
     >
     > On Fri, Feb 17, 2023 at 9:16 AM Dave Taht <[email protected]
    <mailto:[email protected]>> wrote:
     >>
     >> wow! what a blast from the past, and what sadness I felt when
     >> stumbling across Sally Floyd's name in the credits.
     >>
     >> My primary comment is that I wish somehow, in the IETF, we attempted
     >> to address the congestion control problems our wireless transports
     >> have, as that seems to be the principal means of users' access
    to the
     >> internet.
     >>
     >> Secondary comment is what I always harp on, in aiming for an
    internet
     >> that can safely and reliably transport videoconferencing and gaming
     >> traffic while duking it it out with more aggressive capacity seeking
     >> traffic.
     >>
     >>
     >> On Fri, Feb 17, 2023 at 7:41 AM Scheffenegger, Richard
    <[email protected] <mailto:[email protected]>> wrote:
     >> >
     >> > Hello,
     >> >
     >> > In order to facilitate the github based editorial process of a
    revised
     >> > RFC5033 document that outlines the current best practises when
    it comes
     >> > to designing new congestion control mechanisms, I want to invite
     >> > everyone who has commented across various lists and in
    meetings, to
     >> > raise issues and contribute text here:
     >> >
     >> >
     >> > https://rscheff.github.io/rfc5033bis
    <https://rscheff.github.io/rfc5033bis>
     >> >
     >> > https://github.com/rscheff/rfc5033bis/issues
    <https://github.com/rscheff/rfc5033bis/issues>
     >> >
     >> >
     >> > As the home for this work has not yet fully formed yet, I
    created this
     >> > as an individual draft. There are no text changes in
    rfc50333bis-00
     >> > compared to rfc5033, only minor editorial changes due to the
    use of
     >> > markdown for the body of the document.
     >> >
     >> > A number of individuals have already expressed their interest in
     >> > contributing improvements to this document. I am looking
    forward to
     >> > those contributions - either as issues and discussion points,
    or as
     >> > concrete text snippets - in order to reflect the current best
     >> > understanding of the congestion control environment.
     >> >
     >> >
     >> > A new version of I-D,
    draft-scheffenegger-congress-rfc5033bis-00.txt
     >> > has been successfully submitted by Richard Scheffenegger and
    posted to
     >> > the IETF repository.
     >> >
     >> > Name:           draft-scheffenegger-congress-rfc5033bis
     >> > Revision:       00
     >> > Title:          Specifying New Congestion Control Algorithms
     >> > Document date:  2023-02-17
     >> > Group:          Individual Submission
     >> > Pages:          11
     >> > URL:
     >> >
    https://www.ietf.org/archive/id/draft-scheffenegger-congress-rfc5033bis-00.txt 
<https://www.ietf.org/archive/id/draft-scheffenegger-congress-rfc5033bis-00.txt>
     >> > Status:
     >> >
    https://datatracker.ietf.org/doc/draft-scheffenegger-congress-rfc5033bis/ 
<https://datatracker.ietf.org/doc/draft-scheffenegger-congress-rfc5033bis/>
     >> > Html:
     >> >
    https://www.ietf.org/archive/id/draft-scheffenegger-congress-rfc5033bis-00.html 
<https://www.ietf.org/archive/id/draft-scheffenegger-congress-rfc5033bis-00.html>
     >> > Htmlized:
     >> >
    https://datatracker.ietf.org/doc/html/draft-scheffenegger-congress-rfc5033bis 
<https://datatracker.ietf.org/doc/html/draft-scheffenegger-congress-rfc5033bis>
     >> >
     >> >
     >> > Abstract:
     >> >     The IETF's standard congestion control schemes have been
    widely shown
     >> >     to be inadequate for various environments (e.g., high-speed
     >> >     networks).  Recent research has yielded many alternate
    congestion
     >> >     control schemes that significantly differ from the IETF's
    congestion
     >> >     control principles.  Using these new congestion control
    schemes in
     >> >     the global Internet has possible ramifications to both the
    traffic
     >> >     using the new congestion control and to traffic using the
    currently
     >> >     standardized congestion control.  Therefore, the IETF must
    proceed
     >> >     with caution when dealing with alternate congestion control
     >> >     proposals.  The goal of this document is to provide
    guidance for
     >> >     considering alternate congestion control algorithms within
    the IETF.
     >> >
     >> >
     >> >
     >> >
     >> > The IETF Secretariat
     >> >
     >>
     >>
     >> --
     >> This song goes out to all the folk that thought Stadia would work:
     >>
    
https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz
 
<https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz>
     >> Dave Täht CEO, TekLibre, LLC
     >>
     >> --
     >> Congress mailing list
     >> [email protected] <mailto:[email protected]>
     >> https://www.ietf.org/mailman/listinfo/congress
    <https://www.ietf.org/mailman/listinfo/congress>



-- Surveillance Capitalism? Or DIY? Choose:
    https://blog.cerowrt.org/post/an_upgrade_in_place/
    <https://blog.cerowrt.org/post/an_upgrade_in_place/>
    Dave Täht CEO, TekLibre, LLC


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