[Cake] tossing acks into the background queue

Dave Taht dave.taht at gmail.com
Tue Nov 23 02:17:38 EST 2021

On Mon, Nov 22, 2021 at 11:07 PM Sebastian Moeller <moeller0 at gmx.de> wrote:
> Hi Dave,
> On 23 November 2021 06:03:03 CET, Dave Taht <dave.taht at gmail.com> wrote:
> >ages ago I'd (we'd? I really don't remember - forgive me if I've
> >forgotten who actually leaned in on it) written a basic ack-filter in
> >ebpf. this was before cake gained tc actions and my primary use for
> >the tech was for asymmetric connections, and before the good
> >ack-filter arrived, and I was (and remain) unfriendly to this level of
> >dpi.
> >
> >That said, on a symmetric connection, deprioritizing pure acks to the
> >5% background queue nd then turning the cake ack-filter loose on it
> >might actually work.
> >
> >Am I on drugs/is there any point?
> I think at leat when using multiple priority tins forward and reverse traffic should by default use the same tin (I can see non-standard situations that want differential treatment). The argument is that unlike earlier attempts at ingress shaping that tried to throttle reverse ACKs? cake/codel do proper 'hit the brakes' signalling via marking/dropping and we want that signal to reach the other end as quickly as possible, no?

My thought was basically an optional filter that steered all pure acks
(no matter the classification) into the background queue.
Non-pure-acks (sacks) essentially jump the background queue and signal
that loss earlier. The backlog of other acks in background get
delivered out of order, but purely out of order and discarded by the

> Regards
>         Sebastian
> >
> >
> >
> >--
> >I tried to build a better future, a few times:
> >https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
> >
> >Dave Täht CEO, TekLibre, LLC
> >_______________________________________________
> >Cake mailing list
> >Cake at lists.bufferbloat.net
> >https://lists.bufferbloat.net/listinfo/cake
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.

I tried to build a better future, a few times:

Dave Täht CEO, TekLibre, LLC

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