Re: [Detnet] Éric Vyncke's No Objection on draft-ietf-detnet-pof-07: (with COMMENT)

[Balázs Varga A <[e-mail]>]

Hi Éric,

Many thanks for your comments. Please, find responses inline. 
Changes will be posted in some minutes.

Thanks & Cheers
Bala'zs

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Subject: [Detnet] Éric Vyncke's No Objection on draft-ietf-detnet-pof-07: (with COMMENT)

Éric Vyncke has entered the following ballot position for
draft-ietf-detnet-pof-07: No Objection

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COMMENT:
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# Éric Vyncke, INT AD, comments for draft-ietf-detnet-pof-07

Thank you for the work put into this document.

Please find below some non-blocking COMMENT points (but replies would be
appreciated even if only for my own education), and some nits.

Special thanks to Lou Berger for the shepherd's detailed write-up including the
WG consensus and the justification of the intended status.

Other thanks to Pascal Thubert, the Internet directorate reviewer (at my
request), please consider this int-dir review:
https://datatracker.ietf.org/doc/review-ietf-detnet-pof-07-intdir-telechat-thubert-2023-12-20/
(and I have read Balázs' reply)

I hope that this review helps to improve the document,

Regards,

-éric

# COMMENTS (non-blocking)

## Delay varition sensitivity

Our of curiosity, does the DetNet WG intent to publish another document for
another use case: packet-loss-tolerant and delay-variation-sensitive
applications ?

<Balazs> DetNet has published a use-case document (RFC8578). Delay variance 
is considered for "electrical utilities" and "cellular fronthaul networks". 

## Section 3

Considering the 'jitter' as out-of-scope appears quite a strong statement as I
(perhaps wrongly) assume that DetNet is used also in time-sensitive or
real-time applications that are often jitter / delay sensitive.

<Balazs> OK. This statement was the explicitly the result of such a discussion 
in the WG. The target of POF is packet ordering of flows what by nature impacts
jitter. In the last bullet of section 3. it was stated how to deal with that:
      Dealing with delay variation is a DetNet forwarding sub-layer
      target and it can be achieved for example by placing a de-jitter
      buffer or flow regulator (e.g., shaping) function after the POF
      functionality.

## Section 4.1

Is it PRF or PEF in `that arrive at the PRF before the POF ` ?

<Balazs> Good catch it is a typo. Updated to PEF. New version will be posted 
in some minutes.

## Sections 4.4 & 4.5

The whole sections about 'advanced POF and enhancements' are rather
hand-waving. May I suggest to either move it to an appendix, or in a new
section about future considerations, or even remove it completely?

<Balazs> In scenarios with very tight requirements You may need the advanced
POF algorithm and the enhancements. For example if the remaining delay budget
is smaller than the path delay difference, the basic POF algorithm may result in 
too-late packets. 

## Section 5

I wonder about this section title (and content) as no control plane is actually
defined and the POF parameters provisioning was clearly marked as "out of
scope" in the previous section.

<Balazs> The intention was to list explicitly what parameters these functions 
have. This structure was used in the date plane RFCs.

# NITS (non-blocking / cosmetic)

## Section 1

Unsure whether `and the related YANG model is defined in [IEEEP8021CBcv]` is
useful in this document that is not about data models. Up to the authors.

<Balazs> POF uses the sequence number of the packets during ordering. 
CBcv defines sequence number related parameters.

## Section 4.2

Consider not using a numbered list of changing the order of the list because it
is opposed to the order of functions as seen by a packet.

<Balazs> Right. Order changed.

## Section 8

s/bToerless Eckert/Toerless Eckert/ ?

<Balazs> Thanks. Fixed.


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