Subject: [rmcat] Benjamin Kaduk's No Objection on draft-ietf-rmcat-eval-criteria-12: (with COMMENT)

From: Benjamin Kaduk via Datatracker <[email-masked]>
Date: Thu, 05 Mar 2020 02:04:19 -0800

Benjamin Kaduk has entered the following ballot position for
draft-ietf-rmcat-eval-criteria-12: No Objection

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COMMENT:
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Section 1

   media flow's throughput.  Furthermore, the proposed algorithms are
   expected to operate within the envelope of the circuit breakers
   defined in RFC8083 [RFC8083].

The "proposed algorithms" are the congestion-control schemes, not the
evaluation procedures, right?

Section 3.1

   If the congestion control implements, retransmissions or FEC, the

nit: no comma (first one)

Section 4.4

It's too bad that we don't have more specific guidance to give on loss
generation modeling.

Section 4.5.1

   path.  Due to this, if a packet becomes overly delayed, the packets
   after it on that flow are also delayed.  This is especially true for

Doesn't this imply that the real PDV data poitns are not independent and
that we should expect simple PDF modeling to produce inaccurate or
unphysical results?

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From: Joerg Ott <[email-masked]>
Date: Thu, 19 Mar 2020 16:08:24 +0100

Hi Benjamin,

Good point.  Inserted "congestion control" for clarification.

> nit: no comma (first one)

removed

> It's too bad that we don't have more specific guidance to give on loss
We now have a reference to the Gilbert-Elliott model to provide minimal
guidance.

> that we should expect simple PDF modeling to produce inaccurate or

For 4.5.1, which allows reordering, the PDV data points would be
independent.  I am not sure what is meant by unphysical, but if you mean
the sudden reordering that could occur, yes, this could happen.  This is
why we have 4.5.2.  And we make explicit what the impacts of these two
are.

Both random models don't capture queuing behavior properly (cf. the 
definition of x[n]) but is a simple random distribution rather than
derived from a more complex process.  This more random behavior probably
causes more stress on algorithms than smooth increases or decreases of
jitter would.

Best,
Jörg