[tcpm] finalizing CUBIC draft (chairs' view)

Yoshifumi Nishida <nsd.ietf@gmail.com> Fri, 26 August 2022 07:40 UTC

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From: Yoshifumi Nishida <nsd.ietf@gmail.com>
Date: Fri, 26 Aug 2022 00:40:41 -0700
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Subject: [tcpm] finalizing CUBIC draft (chairs' view)
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Hello everyone,
Based on the feedback from the last meeting, the chairs have been
discussing how to finalize the cubic draft.
The below is our current view on the draft.

The slide for the CUBIC draft from the last WG meeting listed 4 discussion
points in the draft.

In these items, we think that the last two points are already addressed now.
With regard to the remaining two points, our views are the following.

Point 1: TCP friendly model in the cubic draft
     We can admit that the model is not valid as the paper describing the
model uses some simplified presumptions.
     But, it doesn't not mean the model will pose serious issues on the
Internet as we haven't seen any evidence yet.

Point 2: Multicative decrease factor during slow-start phase
     We think using the current value: 0.7 may cause more packet losses in
certain cases, but it can work efficiently in other cases.
     We think this is a part of design choices in CUBIC as we haven't seen
any tangible evidence that it can cause serious problems.

We concluded this will require more detailed analysis and evaluations which
can take a longer time.
Based on this, we think these points are NOT needed to be addressed in the
draft while it will be good to add some more explanations for them.
We saw there were several opinions about documenting these points in the
draft during the last meeting. If you have some suggestions here, please
share your opinions.

Please note that this doesn't mean we'll ignore them. we will try to
publish a new version of the CUBIC draft if we find some things on them.

If you have any opinions or comments on the views, please share them with

Yoshi on behalf of tcpm co-chair