Hi Benoit,

Thanks for the thorough review.
We have posted an updated version that hopefully addresses your concerns.

https://datatracker.ietf.org/doc/draft-ietf-opsawg-oam-characterization/08/

Please see my responses below, marked [TM].
Please let us know if there are further comments.

On Wed, Jun 18, 2025 at 6:17 PM Benoit Claise
<[email protected]> wrote:
>
> Tal, Carlos, Adrian,
>
> As document shepherd, I provided my feedback on the version 4. See 
> https://mailarchive.ietf.org/arch/msg/opsawg/zQxI0xpOv1X5VFZDJP0YH1PJ-tU/
> Now looking at the diff between version 4 and 7.
>
> A couple of quick reactions. The draft improved a lot. Thanks Tal for jumping 
> in helping with this document.
> Looking at the long email thread on this topic, I believe this work is 
> (painfully) important. There are some many slightly different OAM definitions 
> in RFCs: someone can always find one definition or one interpretation of it 
> for our own use. While this is apparently good, this is not helping our 
> industry with consistency.
>
> From my previous review, the following points have been addressed
> - draft simplification (removed the "Processing of OAM by Notes, removed 
> Compound OAM, etc)
> - softer language than "you SHALL"
>
>
> - 3.3. Active, Passive, Hybrid, and In-Packet OAM
> [RFC7799] provides clear definitions for active and passive performance 
> assessment such that the construction of metrics and methods can be described 
> as either "Active" or "Passive". Even though [RFC7799] does not include the 
> specific terms "Active", "Passive", or "Hybrid" as modifiers of "OAM", the 
> following terms are used in many RFCs and are provided here for clarity.
>
> You mention RFC7799, great. My question is: are the "Active", "Passive", or 
> "Hybrid" terms define here aligned with RFC7799. If yes, you should stress it.

[TM] Agreed. The section "Active, Passive, Hybrid, and In-Packet OAM"
was updated with explicit text that says that the definitions in the
current document are consistent with RFC7799.

>
> - Since this document is about guidelines, I would had some more text around 
> "Packet Forwarding Treatment OAM"
> Greg has a point that "having equivalence between both topological and QoS 
> aspects makes the results of the observation more operationally useful.".
> Some maybe some text around: Determining whether an OAM mechanism is 
> Equal-Forwarding-Treatment or Different-Forwarding-Treatment is not obvious, 
> except in the case of Hybrid OAM thatis always Equal-Forwarding-Treatment 
> OAM, as the forwarding device hash functions are typically not known. 
> However, if we can determine that the OAM will have the same forwarding 
> treatment, it's best as the results are more operationally useful.
>

[TM] Right. The section "Packet Forwarding Treatment OAM" has been
updated with more discussion about the motivation for
equal-forwarding-treatment.

>
> - I believe that the section 3.4 need more advice for document authors (I 
> already mentioned this in my previous review)
> Let me explain: I see 3 series of OAM adjectives
>
>     [Path-Congruent | Non-Path-Congruent]
>     [ Equal-Forwarding-Treatment | Different-Forwarding-Treatment ]
>     [ Active  |  Passive | Hybrid ]
>
> Should we always be try to characterize OAM with terms in each 3 series?
> Some are redundant:
>     Hybrid  is always Path-Congruent and Equal-Forwarding-Treatment, right?
>     So does it make sense to call RFC 9197 as Path-Congruent 
> Equal-Forwarding-Treatment Hybrid OAM mechanism?
> Some are not possible:
>     Passive & Non-Path-Congruent
>     Hybrid and Non-Path-Congruent
>     etc.
> Think about authors who will need to chose the right terms.
> Along the same lines, it might be nice to take the different examples in the 
> draft (RFC 9197, 9551, 5085) and express them with the terms define here. Or 
> even take as example very simple mechanism, such as ping. Ping is ... I guess 
> Active OAM and I am not sure about the rest:    [Path-Congruent | 
> Non-Path-Congruent]  &   [ Equal-Forwarding-Treatment | 
> Different-Forwarding-Treatment ]

[TM] Agreed. The section "Using Multiple Criteria" has been re-written
and significantly extended with the relevant aspects and several
examples.

>
>
> Regards, Benoit

Thanks,
The authors.

_______________________________________________
OPSAWG mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to