Subject: [Detnet] Intdir last call review of draft-ietf-detnet-bounded-latency-08

From: Ralf Weber via Datatracker <[email-masked]>
Date: Sun, 06 Feb 2022 06:30:10 -0800

Reviewer: Ralf Weber
Review result: Ready with Nits

Moin!

I am an assigned INT directorate reviewer for draft-ietf-detnet-bounded-latency.
These comments were written primarily for the benefit of the Internet Area
Directors. Document editors and shepherd(s) should treat these comments just
like they would treat comments from any other IETF contributors and resolve
them along with any other Last Call comments that have been received. For more
details on the INT Directorate, see
https://datatracker.ietf.org/group/intdir/about/

The draft is very detailed, well written and covers the subject exhaustively. I
think it is ready for publication.

The biggest problem I had was reading all the formulas, that because of the
limitations of being published as an RFC can't be printed nice as you would see
them in a math book. And while they are correct (with one exception) I think
they would be more readable if they had parentheses for groups especially when
going over multiple lines like e.g on page 13:

      backlog_bound = nb_input_ports * max_packet_length + total_in_rate
      * max_delay456

IMHO would be nicer as:

      backlog_bound = ( nb_input_ports * max_packet_length  ) +
                                  ( total_in_rate * max_delay456 )

there is on error on page 19 where the opening parentheses is missing:

      T_A = L_nA + b_h + r_h * L_n/c)/(c-r_h)

could be:

      T_A = ( L_nA + b_h + ( r_h * L_n/c )) / ( c-r_h )

or at least has to be:

      T_A = (L_nA + b_h + r_h * L_n/c)/(c-r_h)

we may have rules formulas in the IETF for this which might be different from
my examples and if we do we should of course follow them, but at least I don't
know of them.

Another nit was that on page 10 there is a description of a T-Spec (Traffice
Specification) of a DeNet flow that is defined in RFC9016 as:
        "Interval: tau, MaxPacketsPerInterval: K, MaxPacketSize: L"
however using the terms defined in RFC9016 section 5.5 it should be:
        "Interval: tau, MaxPacketsPerInterval: K, MaxPayloadSize: L"

Overall I'd like to thank the authors for a very well written document.

So long
-Ralf

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From: Mohammadpour Ehsan <[email-masked]>
Date: Wed, 16 Feb 2022 09:39:05 +0000

Dear Ralf,

Thank you for your comments. We modified the formulas according to your proposal and used the term MaxPayloadSize in the T-SPEC. You can find the new version of the draft in:
https://www.ietf.org/archive/id/draft-ietf-detnet-bounded-latency-09.html

as well as the difference between the new version and the previous version in:
https://www.ietf.org/rfcdiff?url2=draft-ietf-detnet-bounded-latency-09

Best,
Ehsan

--
Ehsan Mohammadpour
PhD candidate at Swiss Federal Institute of Technology (EPFL)
IC IINFCOM, LCA2, INF 011, Station 14, 1015 Lausanne, Switzerland
https://people.epfl.ch/ehsan.mohammadpour

On 6 Feb 2022, at 15:30, Ralf Weber via Datatracker <[email-masked]<mailto:[email-masked]>> wrote:

Reviewer: Ralf Weber

Moin!

IMHO would be nicer as:

could be:

or at least has to be:

So long
-Ralf