Re: [OPSAWG] 🔔 WG Adoption Call for draft-pignataro-opsawg-oam-whaaat-question-mark-03

[Carlos Pignataro <[e-mail]>]

Greg,

Repeating something does not make it so…

You had argued that those were definitions only within the context of DetNet, and each context can have different ones. You really cannot have it both ways. This is confusing. 

I-Ds follow causality — lots of things were approved to then be corrected. 

In-band — out-of-band — what do they really mean when…

There is no “band”

C

Thumb typed by Carlos Pignataro.

Excuze typofraphicak errows

On Apr 15, 2024, at 09:03, Greg Mirsky <[e-mail]> wrote:



Hi Carlos,

I have to repeat that the definitions of terms "in-band OAM", "out-of-band OAM", and "on-path telemetry"

   In-band OAM:  an active OAM method that is in band within the

      monitored DetNet OAM domain when it traverses the same set of

      links and interfaces receiving the same QoS and Packet

      Replication, Elimination, and Ordering Functions (PREOF) treatment

      as the monitored DetNet flow.

   Out-of-band OAM:  an active OAM method whose path through the DetNet

      domain may not be topologically identical to the path of the

      monitored DetNet flow, its test packets may receive different QoS

      and/or PREOF treatment, or both.

   On-path telemetry:  on-path telemetry can be realized as a hybrid OAM

      method.  The origination of the telemetry information is

      inherently in band as packets in a DetNet flow are used as

      triggers.  Collection of the on-path telemetry information can be

      performed using in-band or out-of-band OAM methods.

have been adopted by DetNet WG, approved by IESG and published as part of https://datatracker.ietf.org/doc/rfc9551/" rel="nofollow">RFC 9551. I believe that a constructive approach would be to use the already accepted terminology, not to attempt to negate what has already been achieved in building up the IETF dictionary, particularly in the OAM area.

Regards,

Greg

On Mon, Apr 15, 2024 at 2:00 PM Carlos Pignataro <[e-mail]> wrote:

Dear Greg,

Thank you for the input.

It appears that much of what you write below was already discussed at https://mailarchive.ietf.org/arch/msg/opsawg/IVQzSSU_kvGgopCyCp-8oqK_xmg/" target="_blank" rel="nofollow">https://mailarchive.ietf.org/arch/msg/opsawg/IVQzSSU_kvGgopCyCp-8oqK_xmg/ 

Am I to understand you might be keen on continuing using "in-band OAM" with different meanings depending on the WG or context?

Please find some follow-ups inline below:

On Sun, Apr 14, 2024 at 10:49 AM Greg Mirsky <[e-mail]> wrote:

Dear All,

I've read the latest version of the draft, Please find my notes and questions below:

• All SDOs that standardize methods and/or protocols in the field of OAM recognize that, in the FCAPS network management model, OAM is addressing the 'F' and 'P', i.e., Fault Management and Performance Monitoring methods and protocols. Furthermore, OAM is understood as a collection of various methods and protocols, rather than a single protocol, method, or tool. Hence, it seems like the document must use the same more granular approach in characterizing this or that OAM mechanism, including the possible variance in the application of that mechanism.

CMP: This document intends to Update RFC 6291, a product of the IETF about OAM language usage, with support from its lead editor.

• I was under the impression that the discussion about the unfortunate choice of the original extended form of IOAM, "In-band OAM", has been put to rest with the agreement to extend it as "In-situ OAM". Why bring that discussion back? To revisit the decision of the IPPM WG? If so, then, as I imagine, that must be discussed in the IPPM WG.

CMP: Not really, as explained in the draft already, clearly. See https://mailarchive.ietf.org/arch/msg/opsawg/jREEH1sFOZ-uxZNky-RTggpxkuk/" target="_blank" rel="nofollow">https://mailarchive.ietf.org/arch/msg/opsawg/jREEH1sFOZ-uxZNky-RTggpxkuk/ 

• "Within the IETF, the terms "in-band" and "out-of-band" cannot be reliably understood consistently and unambiguously." That is a very strong and powerful statement that, in my opinion, requires serious analysis. For example, a survey of the IETF community that undoubtedly demonstrates the existence of multiple confronting interpretations that cannot be resolved by a mere wordsmithing. Can the authors cite such a survey and its results?

CMP: The document already contains that analysis. It explains why those terms cannot be reliably understood consistently and unambiguously. 

• And closely following that statement "the terms are not self-defining any more and cannot be understood by someone exposed to them for the first time" seems to break the very foundation of IETF TAO - learn, learn, and learn. I find the expectation of a first-comer to any IETF discussion to be able to fully master all the dictionary and terminology of that group to be, in my experience, a misguided. Through years, I've been suggesting anyone interested in joining and contributing to IETF work to first read (drafts, RFCs) and, most of all, the mail archive. Probably, I've been wasting their time..

CMP: I am not sure I follow what you mean here -- but, (1) https://www.ietf.org/archive/id/draft-tenoever-tao-retirement-03.html" target="_blank" rel="nofollow">https://www.ietf.org/archive/id/draft-tenoever-tao-retirement-03.html (2) **There is no band**!!!!

 

• The following passage brings additional question:

The guidance in this document is to avoid the terms "*-band" and instead find finer-granularity descriptive terms. The definitions presented in this document are for use in all future IETF documents that refer to OAM, and the terms "in-band OAM" and "out-of-band OAM" are not to be used in future documents.

• Is such an overreaching scope of the OPSAWG WG in its charter?

CMP: That is a question for the chairs, but this document originating in opsawg will need to have ietf-wide review...  

• I found a number of references to DetNet OAM that, regrettably, misinterpreted documents approved by DetNet WG and some already published as RFCs. I can only encourage an open communication between the proponents of this work and the DetNet WG rather than an attempt to force something foreign to the essence of Deterministic Networking and the application of OAM in DetNet.
• It appears that the term "Combined OAM", introduced in this document, allows for a combination of "Non-Path Congruent OAM" with "Equal-QoS-Treatment OAM". If that is the case, what do you see as the value of using such "combined OAM"?
• In my reading of Section 3 and references to RFC 7799, I find it getting close to benign misinterpretation of RFC 7799:
• Firstly, RFC 7799 appropriately discusses OAM methods and metrics, i.e., elements of OAM. Hence, because of, what seems like, a misunderstanding of how OAM is composed, the document dismisses RFC 7799 even though that is the fundamental document with 16 references by IETF documents and more by documents in other SDOs.
• In the definition of the "Compound OAM" it is suggested that a combination of Active and Hybrid OAM methods or of Passive and Hybrid OAM methods are distinct examples of Compound OAM. If that is the intention, how to reconcile that with the definition of a Hybrid OAM method in RFC 7799:

   Hybrid Methods are Methods of Measurement that use a combination of

   Active Methods and Passive Methods, to assess Active Metrics, Passive

   Metrics, or new metrics derived from the a priori knowledge and

   observations of the stream of interest.

It does appear, that unless this document updates or obsoletes RFC 7799, a combination of Active and Hybrid or Passive and Hybrid methods will still be a Hybrid OAM method. Actually, according to the following assesment:

[RFC7799] adds to the confusion by describing "passive methods" as "out of band". Following the guidelines of this document, OAM may be qualified according to the terms described in Sections 2 and 3 of this document, and the term "out of band OAM" is not to be used in future documents.

updating RFC 7799 is the intention of this document. Or am I missing something here?

CMP: All of these seem to have been already discussed.

 

As the conclusion. Although the document is well-written, I don't find it addressing a real problem, nor offering a viable, useful solution. Hence, I consider this WG AP utterly premature given that the proposal was not at all socialized outside OPSAWG group.

CMP: This is a WG Adoption, Greg...

 

I hope that the WG Chairs and Responcible AD will discuss the situation with the leadership of IPPM WG, as well as DetNet, MPLS, BFD, BESS, BIER WGs (to name some) that are actively developing, enhancing OAM methods and protocols and could be affected by this proposal.

CMP: Hopefully we catch all those mis-uses in time!!!

Carlos.

 

Regards,
Greg

On Wed, Apr 10, 2024 at 1:06 PM Henk Birkholz <[e-mail]> wrote:

Dear OPSAWG members,

this email starts a call for Working Group Adoption of

> https://www.ietf.org/archive/id/draft-pignataro-opsawg-oam-whaaat-question-mark-03.html" rel="noreferrer nofollow" target="_blank">https://www.ietf.org/archive/id/draft-pignataro-opsawg-oam-whaaat-question-mark-03.html

ending on Thursday, May 2nd.

As a reminder, this I-D summarizes how the term "Operations,
Administration, and Maintenance" (OAM) is used currently & historically
in the IETF and intends to consolidate unambiguous and protocol agnostic
terminology for OAM. The summary includes descriptions of narrower
semantics introduced by added qualifications the term OAM and a list of
common capabilities that can be found in nodes processing OAM packets.

The chairs acknowledge a positive poll result at IETF119, but there has
not been much discussion on the list yet. We would like to gather
feedback from the WG if there is interest to further contribute and
review. As a potential enabler for discussions, this call will last
three weeks.

Please reply with your support and especially any substantive comments
you may have.


For the OPSAWG co-chairs,

Henk

_______________________________________________
OPSAWG mailing list
[e-mail]
https://www.ietf.org/mailman/listinfo/opsawg" rel="noreferrer nofollow" target="_blank">https://www.ietf.org/mailman/listinfo/opsawg

_______________________________________________
OPSAWG mailing list
[e-mail]
https://www.ietf.org/mailman/listinfo/opsawg" rel="noreferrer nofollow" target="_blank">https://www.ietf.org/mailman/listinfo/opsawg