[Detnet] Martin Duke's Discuss on draft-ietf-detnet-flow-information-model-12: (with DISCUSS and COMMENT)

[Martin Duke via Datatracker <[e-mail]>]

Martin Duke has entered the following ballot position for
draft-ietf-detnet-flow-information-model-12: Discuss

When responding, please keep the subject line intact and reply to all
email addresses included in the To and CC lines. (Feel free to cut this
introductory paragraph, however.)


Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
for more information about IESG DISCUSS and COMMENT positions.


The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-detnet-flow-information-model/



----------------------------------------------------------------------
DISCUSS:
----------------------------------------------------------------------

Secs 5.9.6 defines Maximum Reordering Tolerance with an example: "The
difference of sequence number values in
   consecutive packets at the Egress cannot be bigger than
   "MaxMisordering + 1"."

While this definition is actionable, it interacts uncomfortably with Maximum
Consecutive Loss. If MCL < MRT, there are cases where it will violate MRT but
not MCL, which would subvert the usually understood meaning of reordering.

Moreover, if MaxMisordering is 3, the sequence 6, 4, 0 would not trigger this
definition even though there is very significant reordering here.

A better example would be "When a packet arrives at the egress after a packet
with a higher sequence number, the difference between the sequence number
values cannot be bigger than
   "MaxMisordering + 1"."


----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

Sec 1. s/rational/rationale

Sec 1.2 and 1.3. What is the difference between the "flow information model"
that is stated goal and the "flow data model" that is a stated non-goal?

Sec 5.5 Octets/second seems like a very odd unit for Max/Min Payload size. This
should either be Octets, or the metric should be renamed Max/Min Payload Rate,
or something to that effect.

Sec 5.5. the section says a lot about violations of the minimum, but not the
maximum. This approach seems inconsistent.