Re: [tcpm] Proceeding CUBIC draft - thoughts and late follow-up

[Neal Cardwell <[e-mail]>]

Markku, thank you for your clear and comprehensive write-up.

Regarding this particular, somewhat easier point:

On Mon, Jun 6, 2022 at 6:30 AM Markku Kojo <kojo=
[e-mail]> wrote:

> 3 a) The rule for changing alpha to 1 when Wmax is reached in the
>       Reno-friendly region is the correct thing to do during the normal
>       steady state. However, it is incorrect action to take when in the
>       fast convergence mode within the Reno-friendly region because it
>       would act just *opposite* to what CUBIC should do when in the fast
>       convergence mode; instead of slowing down the increase rate during
>       congestion avoidance it actually accelerates because alpha becomes
>       increased to 1 earlier than when not in the fast convergence mode.
>       This seems an obvious mistake with the quite recent modifications
>       to the rfc8312bis.
>

I agree this seems like a clear and straightforward thing to fix. Indeed,
my current draft Linux TCP CUBIC patch series for this "changing alpha to
1" mechanism already uses your suggested approach, and it seems to behave
sensibly.

I have posted a proposed pull request to try to encode this in the draft:
  https://github.com/NTAP/rfc8312bis/pull/146

Please take a look and see what you think. Thanks!

neal