This is quite informative, Greg, but an off-topic red-herring. Perhaps you can 
start a new thread (not referencing this draft) about it.

Carlos.

> On Jun 4, 2025, at 4:07 AM, Greg Mirsky <[email protected]> wrote:
> 
> Hi Tal,
> thank you for pointing out to the management plane mechanism that allows 
> overwriting the p-bits configured by Ethernet switches. I am curious, how 
> many operators use that overwriting capability? I think that you're referring 
> to the following text in RFC 7369:
>       How CCM
>       priority is determined is out of the scope of this document.  Note
>       that the highest priority should be used as the default CCM
>       priority.
> It appears that the question of setting the p-bits is, quite appropriately, 
> left for an operator to decide, as the text about using "the highest 
> priority" (highest compared to what?) is informational.
> On that topic. I am aware of the technique for defect detection in services 
> carrying aggregated flows, which consist of multiple levels of CoS. This 
> technique involves monitoring path connectivity at the highest CoS level 
> among the CoS levels used by the constituent data flows. However, this 
> technique may produce false positives for flows at lower CoS levels, failing 
> to detect loss of connectivity due to severe congestion at lower CoS levels. 
> An operator is expected to evaluate the tradeoff between using per-CoS defect 
> detection and not detecting defects that impact low-level CoS data flows.
> 
> Regards,
> Greg
> 
> Regards,
> Greg
> 
> On Wed, Jun 4, 2025 at 4:46 PM Tal Mizrahi <[email protected] 
> <mailto:[email protected]>> wrote:
>> Hi Greg,
>> 
>> > GIM2>> Before trying to normalize terminology, one needs to understand 
>> > that both topological and forwarding equivencies between OAM and the 
>> > monitored data flow must be provided to make the results of OAM 
>> > observation viable. What is the value of, e.g., performance measurement, 
>> > if there is only topological equivalency between data and OAM flows, but 
>> > respective packets receive different forwarding treatment from the 
>> > network? On the other hand, what would be the operational value of the 
>> > network detection while the topological equivalency is not ensured, but 
>> > only the forwarding equivalency is? The answer is evident in both cases - 
>> > no value. That is why I am asking about the benefit of defining two 
>> > characteristics, which only complicates the definition of what is required 
>> > from an OAM to be a viable operational tool.
>> 
>> [TM] In some cases OAM packets are expected to be treated differently
>> than data traffic that is forwarded through the same path. One example
>> is CCMs, which are sent at the highest possible priority by default
>> (see RFC 7369 for example).
>> 
>> Cheers,
>> Tal.
>> 
>> On Wed, Jun 4, 2025 at 8:31 AM Greg Mirsky <[email protected] 
>> <mailto:[email protected]>> wrote:
>> >
>> > Hi Carlos,
>> > please find my notes below tagged GIM2>>.
>> >
>> > Regards,
>> > Greg
>> >
>> > On Tue, Jun 3, 2025 at 1:21 AM Carlos Pignataro <[email protected] 
>> > <mailto:[email protected]>> wrote:
>> >>
>> >> Greg:
>> >>
>> >> While I’ll defer to Tal for a detailed response, I’ve provided three key 
>> >> points inline.
>> >> See “CMP:” below
>> >>
>> >> On Jun 1, 2025, at 7:49 PM, Greg Mirsky <[email protected] 
>> >> <mailto:[email protected]>> wrote:
>> >>
>> >> Hi Tal,
>> >> thank you for explaining updates. Please find my follow-up notes below 
>> >> tagged GIM>>.
>> >>
>> >> Regards,
>> >> Greg
>> >>
>> >> On Thu, May 29, 2025 at 5:59 PM Tal Mizrahi <[email protected] 
>> >> <mailto:[email protected]>> wrote:
>> >>>
>> >>> Hi Greg,
>> >>>
>> >>> Thanks again for reviewing the draft. Your comments for the previous
>> >>> versions have helped in improving the draft.
>> >>> Please see my responses to the latest comments that you have sent to
>> >>> the authors off-list when you kindly reviewed an intermediate version
>> >>> of the draft.
>> >>>
>> >>>
>> >>> On Tue, May 13, 2025 at 8:38 PM Greg Mirsky <[email protected] 
>> >>> <mailto:[email protected]>> wrote:
>> >>> >
>> >>> > Hi Tal,
>> >>> >
>> >>> > Thank you for your work on addressing my comments. I reviewed the 
>> >>> > working version of the draft and have some comments and questions, 
>> >>> > which are below.
>> >>> > Section 2:
>> >>> >
>> >>> > It is noted that "A frequently encountered case is the use of 
>> >>> > "in-band" to mean either in-packet or on-path." If that is the case, 
>> >>> > and there are many IETF documents that use these interpretations of 
>> >>> > "in-band," it seems like it would be easy to provide several 
>> >>> > references in support of that assumption.
>> >>>
>> >>> [TM] Following your comment we have focused the following two paragraphs.
>> >>> The following paragraph demonstrates the use of the term "in-band" in
>> >>> the context of path-congruent OAM:
>> >>>
>> >>>       Connectivity Verification (VCCV), described is Section 6 of
>> >>>       [RFC5085] as "The VCCV message travels in-band with the Session
>> >>>       and follows the exact same path as the user data for the session".
>> >>>       Thus, the term "in-band" in [RFC5085] refers to using the same
>> >>>       path as the user data.  This term is also used in Section 2 of
>> >>>       [RFC6669] with the same meaning, and the word "congruent" is
>> >>>       mentioned as synonymous.
>> >>
>> >> GIM>> I don't think that your interpretation of "in-band" in RFC 5085 is 
>> >> accurate. The VCCV message not only traverses the same path as a data 
>> >> packet because the same labels are applied along the path, but it also 
>> >> receives the same forwarding treatment by the network because the same 
>> >> Traffic Class is used for the VCCV message as for the data packet. Thus, 
>> >> it is in-band with the monitored data flow, and topological equivalence 
>> >> is only one element, while it must be complemented by the QoS equivalence.
>> >>
>> >>
>> >> CMP: As an author of RFC 5085, I can confirm that you are completely 
>> >> wrong on this.
>> >
>> > GIM2>> That is your personal opinion, not the opinion of other authors, 
>> > and even less the opinion of PWE3 (later PALS) WG. As the PALS WG is 
>> > winding down, the MPLS WG may be the community to provide a more 
>> > authoritative interpretation of RFC 5085.
>> >>
>> >>
>> >> CMP: That said, you do not need to be an author to know this, you can 
>> >> actually **read** the RFC, where it says:
>> >> CMP: "in-band (i.e., following the same data-plane faith as PW data).”
>> >> CMP: “ travels in-band with the Session and follows the exact same path 
>> >> as the user data for the session"
>> >> CMP: Let’s not make up ‘interpretations’.
>> >>
>> >>
>> >>>
>> >>> On the other hand, the following paragraph demonstrates the use of
>> >>> "in-band" in the context of in-packet OAM:
>> >>>
>> >>>       Initially, "In situ OAM" [RFC9197] was also referred to as "In-
>> >>>       band OAM" [I-D.brockners-inband-oam-data], but was renamed due to
>> >>>       the overloaded meaning of "In-band OAM".  Further, [RFC9232] also
>> >>>       intertwines the terms "in-band" with "in situ", though
>> >>>       [I-D.song-opsawg-ifit-framework] settled on using "in Situ".
>> >>>       Other similar uses, including [P4-INT-2.1] and
>> >>>       [I-D.kumar-ippm-ifa], still use variations of "in-band", "in
>> >>>       band", or "inband".
>> >>
>> >> GIM>>  I find historical references not relevant to my questions. 
>> >> Furthermore, AFAICS, [I-D.song-opsawg-ifit-framework], and 
>> >> [I-D.kumar-ippm-ifa], as individual drafts, do not reflect an agreement 
>> >> of any of IETF WGs. Additionally, both individual drafts have been 
>> >> expired for over 6 months. On the other hand, several RFCs published by 
>> >> IETF, e.g., RFC 9772 give clear and useful interpretation of
>> >>
>> >>
>> >> CMP: This is *exactly* the problem that we are trying to solve with this 
>> >> document, and truly an argument for moving forward with this document.
>> >> CMP: You are citing protocol-specific context-specific wg-specific 
>> >> definitions.
>> >> CMP: If the goal is to write a lot of RFCs with almost overlapping text, 
>> >> sure.
>> >> CMP: If the goal is clarity and removing ambiguity, the per-protocol 
>> >> approach does not work.
>> >
>> > GIM2>> Before trying to normalize terminology, one needs to understand 
>> > that both topological and forwarding equivencies between OAM and the 
>> > monitored data flow must be provided to make the results of OAM 
>> > observation viable. What is the value of, e.g., performance measurement, 
>> > if there is only topological equivalency between data and OAM flows, but 
>> > respective packets receive different forwarding treatment from the 
>> > network? On the other hand, what would be the operational value of the 
>> > network detection while the topological equivalency is not ensured, but 
>> > only the forwarding equivalency is? The answer is evident in both cases - 
>> > no value. That is why I am asking about the benefit of defining two 
>> > characteristics, which only complicates the definition of what is required 
>> > from an OAM to be a viable operational tool.
>> >>
>> >>
>> >>
>> >> "in-band OAM":
>> >>    *  In-band OAM is an active or hybrid OAM method, as defined in
>> >>       [RFC7799], that traverses the same set of links and interfaces and
>> >>       receives the same Quality of Service treatment as the monitored
>> >>       object.  In this context, the monitored object refers to either
>> >>       the entire Geneve tunnel or a specific tenant flow within a given
>> >>       Geneve tunnel.
>> >> As well as in RFC 9551 we find the following interpretations of in-band 
>> >> and out-of-band OAM:
>> >>    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.
>> >>
>> >>>
>> >>>
>> >>> > I think the following assertion, also without any reference, is 
>> >>> > unsubstantiated.
>> >>> >
>> >>> >    Within the IETF, the terms "in-band" and "out-of-band" cannot be
>> >>> >
>> >>> >    reliably understood consistently and unambiguously.
>> >>> >
>> >>>
>> >>> [TM] This assertion is demonstrated throughout Section 2.1, including
>> >>> the two paragraphs cited above. Another relevant paragraph that
>> >>> demonstrates this point is the following:
>> >>>
>> >>>    There are many examples of "in-band OAM" and "out-of-band OAM" in
>> >>>    published RFCs.  For instance, the term "in-band" appears in both
>> >>>    [RFC5085] and [RFC9551].  While the context in each of these
>> >>>    documents is clear, the term carries different meanings in each case.
>> >>
>> >> GIM>> As noted above, I find that the interpretations of "in-band OAM" in 
>> >> RFC 5085, RFC 9551 (and RFC 9772) are, if not identical, then very close, 
>> >> as both require topological and QoS equivalencies between OAM and data 
>> >> packets.
>> >>
>> >>
>> >> CMP: Clearly you are “reading’ much beyond the words on the RFCs. RFC 
>> >> 5085 did not consider QoS.
>> >> CMP: Please search all archives and share one mention of QoS along with 
>> >> 5085.
>> >> CMP: Now, “the very close” is the whole problem. You are inclined in 
>> >> defining the same term, in-band, with **very close** but not the same 
>> >> definitions per WG...
>> >
>> > GIM2>> Asked and answered. If the OPSAWG is looking for the authoritative 
>> > opinion on RFC 5085, it would be reasonable to post the question to the 
>> > MPLS WG.
>> >>
>> >>
>> >>
>> >>>
>> >>> > More so, the Routing Area has published or is in the process of 
>> >>> > publishing several documents (passed the IESG review) that use the 
>> >>> > terms "in-band" and "out-of-band"—for example, RFC 9551 and 
>> >>> > draft-ietf-nvo3-geneve-oam. At least in the Routing Area, these terms 
>> >>> > seem to be understood unambiguously. If that is the case, perhaps 
>> >>> > other WGs can look at how the WGs in the Routing Area interpret these 
>> >>> > terms.
>> >>> >
>> >>> > That is followed by
>> >>> >
>> >>> > "Context-specific definitions of these terms are inconsistent and 
>> >>> > therefore cannot be generalized."
>> >>> >
>> >>> > That, without any example, reference to where the interpretation of 
>> >>> > "in-band" and "out-of-band" terms is established seems like an 
>> >>> > unsubstantiated assertion.
>> >>>
>> >>> [TM] Indeed, RFC9551 is mentioned 5 times in the draft, and its
>> >>> interpretation of "in-band" is clear. The point that is emphasized in
>> >>> the draft is regarding inconsistency across the RFC series:
>> >>>
>> >>>    For instance, the term "in-band" appears in both
>> >>>    [RFC5085] and [RFC9551].  While the context in each of these
>> >>>    documents is clear, the term carries different meanings in each case.
>> >>
>> >> GIM>> Asked and answered above.
>> >>>
>> >>>
>> >>> >
>> >>> > Section 2.1
>> >>> >
>> >>> > AFAIK, the term congruent in geometry is not limited to the definition 
>> >>> > proposed in this draft. Hence, the proposed term "Path Congruent" is 
>> >>> > re-defining the original interpretation of the term "congruent" by 
>> >>> > omitting that congruence between two figures is not limited to them 
>> >>> > being of the same size, shape, and also traversing the same set of 
>> >>> > points, but that the congruence may be demonstrated by moving figures, 
>> >>> > e.g., rotating, flipping. Thus, the proposed term seems as artificial 
>> >>> > and non-intuitive as "in-band".
>> >>>
>> >>> [TM] The term "congruent" is used figuratively in the current draft,
>> >>> and is therefore not identical to the geometrical definition.
>> >>
>> >> GIM>>  Can you point me to where in the document it is clarified that the 
>> >> interpretation of "congruent" departs from the definition accepted 
>> >> everywhere except in this draft? Isn't that the same as the document 
>> >> states regarding the use of "in-band" for OAM packets?
>> >>>
>> >>>
>> >>> > Reference to RFC 6669 in the context of using "congruent" vs. 
>> >>> > "in-band" terminology is incomplete and inaccurate. Firstly, 
>> >>> > "congruent" is used only once while "in-band" - is used six times in 
>> >>> > RFC 6669. But more importantly, "share their fate with data packets" 
>> >>> > is not reflected in the proposed definition since the fate sharing 
>> >>> > includes not only topological equivalence between the path traversed 
>> >>> > by the monitored data flow and the OAM packets, but also that they 
>> >>> > received the same QoS treatment. Thus, the reference to RFC 6669 more 
>> >>> > in support of "in-band" terminology rather than the proposed in the 
>> >>> > draft.
>> >>>
>> >>> [TM] Following your comment we have rephrased the sentence referring to 
>> >>> RFC6669:
>> >>>
>> >>>       Thus, the term "in-band" in [RFC5085] refers to using the same
>> >>>       path as the user data.  This term is also used in Section 2 of
>> >>>       [RFC6669] with the same meaning, and the word "congruent" is
>> >>>       mentioned as synonymous.
>> >>
>> >> GIM>> As I pointed out above, I believe that your interpretation of how 
>> >> "in-band" is interpreted in RFC 5085 falls short of recognizing that a 
>> >> VCCV message experiences not only topological equivalency with the data 
>> >> packet but also QoS equivalency.
>> >>>
>> >>>
>> >>> > The introduction of "in-packet OAM" seems confusing and unnecessary:
>> >>> >
>> >>> >       In-Packet OAM:
>> >>> >
>> >>> >          The OAM information is carried in the packets that also carry
>> >>> >
>> >>> >          the data traffic.  This was sometimes referred to as 
>> >>> > "in-band".
>> >>> >
>> >>> > Firstly, this definition repeats the definition of Hybrid OAM in RFC 
>> >>> > 7799. Secondly, note in the second sentence without a reference to the 
>> >>> > IETF document is unsubstantiated and erroneous as it is not how 
>> >>> > in-band OAM is defined in the IETF approved documents, e.g., RFC 9551 
>> >>> > and draft-ietf-nvo3-geneve-oam. Furthermore, characterization of IOAM 
>> >>> > as an example of in-packet OAM misses cases when IOAM is combined with 
>> >>> > active OAM, e.g., STAMP, as proposed in draft-ietf-ippm-stamp-ext-hdr. 
>> >>> > Classification per RFC 7799 is clear - such combination is an example 
>> >>> > of Hybrid OAM. But how does the proposed terminology work in this 
>> >>> > case? According to "In situ OAM [RFC9197] is an example of "In-Packet 
>> >>> > OAM", it is In-packet OAM. On the other hand, packet doesn't carry 
>> >>> > data traffic but is a specially constructed test packet, and, per RFC 
>> >>> > 7799 is an example of Hybrid OAM. Seems like introduction of the new 
>> >>> > class of In-packet OAM is superfluous, and terminology defined in RFC 
>> >>> > 7799, already broady used in IETF documents, is sufficient.
>> >>>
>> >>> [TM] Following your comment we have added a more detailed explanation
>> >>> highlighting the difference between hybrid and in-packet OAM by
>> >>> providing an example of hybrid OAM which is not in-packet OAM:
>> >>>
>> >>>       In situ OAM [RFC9197] is an example of "In-Packet OAM", given that
>> >>>       it: '...records OAM information within the packet while the packet
>> >>>       traverses a particular network domain.  The term "in situ" refers
>> >>>       to the fact that the OAM data is added to the data packets rather
>> >>>       than being sent within packets specifically dedicated to OAM.'  On
>> >>>       the other hand, direct loss measurement [RFC6374] is an example of
>> >>>       "Hybrid OAM" which is not classified as "In-Packet OAM".
>> >>
>> >> GIM>> IOAM in RFC 9197 is classified as:
>> >>    In terms of the classification given
>> >>    in [RFC7799], IOAM could be portrayed as Hybrid Type I.
>> >> And this document, as it appears, defines IOAM as an "in-packet OAM". 
>> >> Does that updates RFC 9197 by changing IOAM classification? Or tries to 
>> >> introduce a new term for Hybrid Type I? Can you please clarrify that in 
>> >> the document?
>> >>>
>> >>>
>> >>> >
>> >>> > What could be the benefit of separating the topological aspect of OAM 
>> >>> > from the QoS behavior OAM experiences in the network? For example, a 
>> >>> > Path non-congruent OAM cannot provide useful information about the 
>> >>> > monitored data flow. The same is the case of 
>> >>> > Different-Forwarding-Treatment OAM. Only Path Congruent with 
>> >>> > Equal-Forwarding-Treatment OAM can produce information that is 
>> >>> > relevant to the monitored data flow. And that is how RFC 9551 defines 
>> >>> > In-band OAM for a DetNet domain. It seems reasonable to generalize 
>> >>> > definitions already accepted by the Routing Area through an open 
>> >>> > discussion with WGs, including the recognized center of competence in 
>> >>> > the Performance measurement OAM, the IPPM WG.
>> >>>
>> >>> [TM] One example, which is cited in the draft is RFC5085, defining VCCV:
>> >>>
>> >>>       Connectivity Verification (VCCV), described is Section 6 of
>> >>>       [RFC5085] as "The VCCV message travels in-band with the Session
>> >>>       and follows the exact same path as the user data for the session".
>> >>>       Thus, the term "in-band" in [RFC5085] refers to using the same
>> >>>       path as the user data.
>> >>>
>> >>> While "in-band" in this case refers to using the same path, there is
>> >>> no guarantee about Equal-Forwarding-Treatment.
>> >>
>> >> GIM>> As I noted above, a VCCV message uses not only the same label 
>> >> information but the same Traffic Class marking as the data flow.
>> >>>
>> >>>
>> >>> >
>> >>> > My conclusion, proposed "In-packet OAM" is superfluous and 
>> >>> > classification defined in RFC 7799 is sufficient. Separation of 
>> >>> > topological aspects of OAM from the QoS treatment OAM packet receives 
>> >>> > from the network is artificial and doesn't add any value. If anyone 
>> >>> > cannot accept the terminology defined in RFC 9551, perhaps 
>> >>> > "in-flow/out-of-flow" may be defined. As the document exists now, I 
>> >>> > don't find it helpful, and, certainly, not at the level of the Best 
>> >>> > Current Practice document.
>> >>> >
>> >>> > Regards,
>> >>> > Greg
>> >>> >
>> >>> >
>> >>>
>> >>> Thanks,
>> >>> Tal.
>> >>>
>> >>> On Thu, May 29, 2025 at 12:22 AM Greg Mirsky <[email protected] 
>> >>> <mailto:[email protected]>> wrote:
>> >>> >
>> >>> > Hi Tal,
>> >>> > I have read the latest version of the draft, and I don't find that any 
>> >>> > of my concerns have been addressed. Let us continue the discussion.
>> >>> >
>> >>> > Regards,
>> >>> > Greg
>> >>> >
>> >>> > On Thu, May 15, 2025 at 9:14 AM Tal Mizrahi <[email protected] 
>> >>> > <mailto:[email protected]>> wrote:
>> >>> >>
>> >>> >> Hi Greg,
>> >>> >>
>> >>> >> Thanks again for your review, and for some additional comments you
>> >>> >> sent us offline about an intermediate version you reviewed.
>> >>> >>
>> >>> >> We have revised the document in an effort to address the main comments
>> >>> >> you raised.
>> >>> >>
>> >>> >> Link to the current draft:
>> >>> >> https://datatracker.ietf.org/doc/draft-ietf-opsawg-oam-characterization
>> >>> >>
>> >>> >> Diff compared to version 04 (which you previously reviewed):
>> >>> >> https://author-tools.ietf.org/iddiff?url1=draft-ietf-opsawg-oam-characterization-04&url2=draft-ietf-opsawg-oam-characterization-06&difftype=--html
>> >>> >>
>> >>> >> Please let us know what you think.
>> >>> >>
>> >>> >> Thanks,
>> >>> >> Tal.
>> >>> >>
>> >>> >> On Sun, Oct 27, 2024 at 1:27 AM Greg Mirsky <[email protected] 
>> >>> >> <mailto:[email protected]>> wrote:
>> >>> >> >
>> >>> >> > Dear All,
>> >>> >> > I read the draft. Although I find it easy to read, I don't see its 
>> >>> >> > publication in its current form to be helpful to the IETF community 
>> >>> >> > and the networking industry in general. Furthermore, despite 
>> >>> >> > several calls for a broader discussion by WGs outside the OPSAWG, I 
>> >>> >> > don't find any threads in the mail archive. It seems like the lack 
>> >>> >> > of a wider discussion of the proposed changes in terminology 
>> >>> >> > related to OAM protocols and methods contradicts the intended BCP 
>> >>> >> > status of the document as not sufficiently discussed by the IETF 
>> >>> >> > community involved in the development of OAM 's Fault management 
>> >>> >> > (FM) and Performance measurement (PM) protocols. I encourage 
>> >>> >> > reaching out to those WGs who are actively involved in developing 
>> >>> >> > and extending these OAM mechanisms. For example, IPPM WG is the 
>> >>> >> > recognized center of competence in developing OAM PM protocols. 
>> >>> >> > Many WGs in the Routing Area define various network layers that 
>> >>> >> > require specification of the applicability of the existing FM and 
>> >>> >> > PM OAM protocols. AFAICS, these groups have been using terminology 
>> >>> >> > that this document proposes to uplift and replace with a very 
>> >>> >> > different set of terms. That would be confusing and detrimental to 
>> >>> >> > the work of these groups. Please find my notes on the draft below.
>> >>> >> > Introduction
>> >>> >> >
>> >>> >> > I disagree with the assertion that RFC 7799 "does not substantially 
>> >>> >> > discuss OAM". OAM is the collection of methods and protocols in the 
>> >>> >> > FCAPS network management model and framework that fulfill 'F' 
>> >>> >> > (fault management) and 'P' (performance monitoring) functions. As 
>> >>> >> > RFC 7799 defined the principles of classification of performance 
>> >>> >> > measurement methods, it is an integral part of any discussion 
>> >>> >> > related to OAM.
>> >>> >> >
>> >>> >> > In-Band and Out-of-Band OAM
>> >>> >> >
>> >>> >> > What is the basis for the following assertion?
>> >>> >> >
>> >>> >> >    Within the IETF, the terms "in-band" and "out-of-band" cannot be
>> >>> >> >
>> >>> >> >    reliably understood consistently and unambiguously.
>> >>> >> >
>> >>> >> > Perhaps that is because the document was not discussed with DetNet 
>> >>> >> > WG, which defined these terms in RFC 9551. Additionally, these 
>> >>> >> > terms are accepted and consistenly used in OAM documents by RAW and 
>> >>> >> > BIER WGs (as noted in Section 2 of the draft). The argument that 
>> >>> >> > interpreting these terms may require familiarity with the context 
>> >>> >> > is too weak for the IETF community, as it is customary to expect 
>> >>> >> > that a reader of an IETF document is familiar with the terminology 
>> >>> >> > specific to the subject and established in prior publications.
>> >>> >> >
>> >>> >> > The use of the term "conrguent" is really confusing for anyone 
>> >>> >> > familiar with its interpretation in geometry:
>> >>> >> >
>> >>> >> > identical in form; coinciding exactly when superimposed
>> >>> >> >
>> >>> >> > Let me share a simple expmple to demonstrate where term "congruent" 
>> >>> >> > fails. Imagine a network with ECMP as below:
>> >>> >> >
>> >>> >> >                    C----------D
>> >>> >> >                  /                  \
>> >>> >> >
>> >>> >> > A----------B                    E------------F
>> >>> >> >                \                    /
>> >>> >> >
>> >>> >> >                 G-------------I
>> >>> >> >
>> >>> >> > Graphs A-B-C-D-E-F and A-B-G-I-E-F are congruent as one can be 
>> >>> >> > superimposed onto another using mirror reflection. However, if OAM 
>> >>> >> > packets follow the former while data traverse the latter, an 
>> >>> >> > operator would get information that does not reflect the state of 
>> >>> >> > the monitored data flow.
>> >>> >> >
>> >>> >> > I find the assertion that newly defined "In-packet OAM" is 
>> >>> >> > analogous to how DetNet OAM defines in-band OAM and 
>> >>> >> > "Dedicated-Packet OAM" is analogous to how "out-of-band" is used in 
>> >>> >> > DetNet OAM a clear misrepresentation that, AFAICS, is the result of 
>> >>> >> > not discussing this document outside of OPSAWG.
>> >>> >> > Furthermore, IPPM WG discussed and adopted the draft that combines 
>> >>> >> > the use of IOAM and STAMP. How would such a method be characterized 
>> >>> >> > in relation to the packet?
>> >>> >> > RE: the change from "In-band" to "In-situ" terminology. The 
>> >>> >> > proponents of using "In-band" missed that a specially constructed 
>> >>> >> > test packet, i.e., active OAM per RFC 7799, can also be in-band 
>> >>> >> > with the monitored data flow. Once that was cleared, then the 
>> >>> >> > interpretation of 'I' in IOAM was changed.
>> >>> >> > Please provide a reference where RFC 9551 Framework of Operations, 
>> >>> >> > Administration, and Maintenance (OAM) for Deterministic Networking 
>> >>> >> > (DetNet) "uses Combined OAM". AFAIK, it does not.
>> >>> >> > And note that BIER WG in draft-ietf-bier-oam-requirements also uses 
>> >>> >> > in-band/out-of-band terminology in a manner consistent with its use 
>> >>> >> > by DetNet and RAW WGs.
>> >>> >> >
>> >>> >> > Active, Passive, Hybrid, and Compound OAM
>> >>> >> >
>> >>> >> > RFC 7799 defines a hybrid performance measurement method as 
>> >>> >> > combining elements of passive and active measurement methods. Given 
>> >>> >> > that, a combination of active and passive is already characterized 
>> >>> >> > as hybrid per RFC 7799. Also, combinations that include a hybrid 
>> >>> >> > method are hybrid methods. Hence, the introduction of the term 
>> >>> >> > "Compound" is superfluous.
>> >>> >> >
>> >>> >> >
>> >>> >> > In conclusion, this document is not ready for publication in its 
>> >>> >> > current form. It must be discussed with groups that are recognized 
>> >>> >> > centers of competence in the field of network OAM protocols, both 
>> >>> >> > FM OAM and PM OAM. The feedback from these discussions must be 
>> >>> >> > reflected in the document, and then its value must be reassessed.
>> >>> >> >
>> >>> >> > Regards,
>> >>> >> > Greg
>> >>> >> >
>> >>> >> >
>> >>> >> > On Mon, Oct 21, 2024 at 9:25 AM Joe Clarke (jclarke) 
>> >>> >> > <[email protected] 
>> >>> >> > <mailto:[email protected]>> wrote:
>> >>> >> >>
>> >>> >> >> This starts a two week WG LC 
>> >>> >> >> https://datatracker.ietf.org/doc/draft-ietf-opsawg-oam-characterization/.
>> >>> >> >>   The authors have been polled and there is no known IPR on this 
>> >>> >> >> work that has been disclosed at this time.
>> >>> >> >>
>> >>> >> >>
>> >>> >> >>
>> >>> >> >> Please post comments and thoughts on this document’s readiness to 
>> >>> >> >> the list.  We ultimately want to run publication of this in 
>> >>> >> >> conjunction with the on-path telemetry document.  Thanks to Greg 
>> >>> >> >> Mirsky who agreed to shepherd this draft.
>> >>> >> >>
>> >>> >> >>
>> >>> >> >>
>> >>> >> >> The WG LC will run until November 4.
>> >>> >> >>
>> >>> >> >>
>> >>> >> >>
>> >>> >> >> Thanks.
>> >>> >> >>
>> >>> >> >>
>> >>> >> >>
>> >>> >> >> Joe
>> >>> >> >>
>> >>> >> >>
>> >>> >> >>
>> >>> >> >> _______________________________________________
>> >>> >> >> OPSAWG mailing list -- [email protected] <mailto:[email protected]>
>> >>> >> >> To unsubscribe send an email to [email protected] 
>> >>> >> >> <mailto:[email protected]>
>> >>> >> >
>> >>> >> > _______________________________________________
>> >>> >> > OPSAWG mailing list -- [email protected] <mailto:[email protected]>
>> >>> >> > To unsubscribe send an email to [email protected] 
>> >>> >> > <mailto:[email protected]>
>> >>
>> >>

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