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 RFC
9551 <https://datatracker.ietf.org/doc/rfc9551/>. 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 <cpign...@gmail.com> 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/
>
> 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 <gregimir...@gmail.com>
> 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/
>
>>
>> - "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 (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 <henk.birkholz@ietf.contact>
>> 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
>>>
>>> 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
>>> OPSAWG@ietf.org
>>> https://www.ietf.org/mailman/listinfo/opsawg
>>>
>> _______________________________________________
>> OPSAWG mailing list
>> OPSAWG@ietf.org
>> https://www.ietf.org/mailman/listinfo/opsawg
>>
>
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