I am the assigned Gen-ART reviewer for this draft. The General Area Review Team (Gen-ART) reviews all IETF documents being processed by the IESG for the IETF Chair. Please treat these comments just like any other last call comments. For more information, please see the FAQ at . Document: draft-ietf-ccamp-optical-impairment-topology-yang-20 Reviewer: Elwyn Davies Review Date: 2025-11-15 IETF LC End Date: 2025-11-10 IESG Telechat date: 2025-11-20 Summary:Ready with nits as far as the explanatory text is concerned. I am afraid that my knowledge of the deep technology of fibre optic networks is about 20 years out of date so I cannot offer any opinions of the accuracy of the technical details of the YANG and its appropriateness for current optical network configuration - but it seems to make sense and provide the sort of support that might be needed. I apologise for the lateness of the review - I had to do a certain amount of background catch-up - and it is a meaty document! There appear to be a few places where some additional pointers to external document might be needed for things which may be common knowldege for afficianados but are less so for newbies. Major issues: None Minor issues: None Nits/editorial comments: General: s/e.g. /e.g., / (7 cases starting in s1.1) General: s/like/such as/ (6 cases starting in para 2 of s2.3.1, next to last para of s2.4, paras 1 and 2 of s2.6. last para of s2.6.1, para 1 of s2.6.2 ) Abstract: It would be worth expanding TE (Traffic Engineering) in the abstract and mentioning that, in general. it augments RFC 8795. Abstract, para 2: Suggest s/for the impairment-aware/supporting the provisioning of optical connections in impairment-aware/ s1, first sentence: s/a wavelength/wavelength/ s1, para 4: This para refers specifically to WSONs and omits SSONs. Does the MDSC technology not apply to SSONs? s1. next to last para: It would be more elegant to s/E.g../For example,/ s1, last para: s/new/second generation/ [new is not future proof] s1.1, para 14, last sentence: The phrase 'may only contain OTs' gave me pause. Just checking that this is intended to imply that this is one possible case of the node. If so, it could be better to say 'might only'. 'May only' got me thinking that this could be a restriction on the make up. s1.1, para 16 and s2.3.3, para 3: the XML section cross reference inserts 'Section xxxx' automatically so remove 'section' before the cross reference. s2.1, para 2: Expand DWDM on first use. s2.1. Figure 1: Quibble: Define MCG before OTS MCG and OMS MCG. s2.3, Figures 2, 3 and 4: Do the Kn labels have any significance? s2.3, Figures 2 and 3: Do the X markings have any significance beyond marking the centre frequency of the channel? s2.4, para 1: s/today/at the time of writing/ s2.3, para 8: s/in transmit direction/in the transmit direction/; s2.4, para 10: s/allowing to control/allowing control of/, s/which allows to control the/which allows control of the/ s2.4, para before Figure 5: s/This filter and/These filter and/ s2.6, para 1: s/like for example/such as, for example,/ s2.6, para 1: The term 'client layer' makes its first appearance in this document here. It is not really inherited from any of the RFCs referred to in the Terminology section. The only mention I could find of the term is a definition specific to RFC 7698 given in Section 1 of that document. I think it needs a definition. Further, I am not sure what the phrase 'addressing layer 0 aspects of transponders' actually applies to. Is this something which ought to be said at the beginning about the scope of the whole document. i.e., that it addresses just the layer 0 aspects of all components mentioned? Please clarify. s2.6, para 3: The etc at the end of this paragraph leaves one hanging without complete knowledge of what properties are covered. Will I find out how it is completed later? If so some pointers to sections where the complete lists can be seen would be useful. s2.6.1, para 1: Expand SDO on first use (not deemed to be well-known). s2.6.1, para 1: s/to consider other/consideration of other/, s/will be available/might be available/ s2.6.1, para 1: It might be worth repeating the definition of "Transversely compatible dense wavelength division multiplexing" (DWDM) i.e., that it is a standard that ensures DWDM equipment from different vendors can work together in a network. s2.6.1, para 2, last sentence: s/as transceiver capability/as a transceiver capability/ s2.6.2, 1st bullet: Expand FEC. s2.6.3, para 1: s/allows to encode, explicitly,/allows the encoding, explicitly, of/ s2.6.4, para 4: s/allows to describe/allows the description of/ s2.7, para 6 (just before Figure 7): s/as the transmitter/than the transmitter/ s2.7, para 7: s/the capability whether/the capability that/ s2.10, para 4: s/ Section 4 intend/Section 4 intends/ s2.10, Figures 9 and 10: What is the significance of the term 'Colored OT'? Is this known from some other context? s2.11.1, para 1: s/in transmit direction/in the transmit direction/; s/in receive direction/in the receive direction/ s2.11.1, para 3: s/as leaf list of the otsi/as a leaf list of the OTSi/ s2.11.1, para 4: s/in forward direction/in the forward direction/; s/in reverse direction/in the reverse direction/ s2.11.1, bullet points 1-3: s/in reverse direction/in the reverse direction/ (3 places) s2.11.1, para 11 and s2.11.1.2, para 5: s/Like/Similarly/ s2.11.1, para 11: s/in forward and reverse direction/in the forward and reverse directions/ s2.11.1, last para: s/in following/in the following/; s/provided how these/provided as to how these/ s2.11.1.1, para 5: s$in transmit/forward direction$in the transmit/forward direction$; s$in receive/reverse direction$in the receive/reverse direction$ s2.11.1.1. para 7: Does the term local-link-connectivity list need a reference to its definition which may be in draft-ietf-teas-yang-te-topo or RFC 8795? s2.11.1.2, para 4: s$in transmit/forward direction$in the transmit/forward direction$; s$in receive/reverse direction$in the receive/reverse direction$ s2.11.1.2 para 6: s/the protected ad-drop/the protected add-drop/ s2.11.1.1 and .2, titles of Figures 15-18: s/WDM-TE node/WDM-TE-node/ s2.11.1.3, paras 1 and 4: Do 'The difference compared to use case (i)' and 'in the same way as for use case (i)' refer (again) to s2.11.1.1 - there doesn't seem to be any usage of (i) as a bullet label around here. s2.11.2.1, para 1: Missing closing bracket after 'TE-link ("te-link-attributes"' s3 in 'grouping amplifier-params: container operational: leaf type-variety' s/This attributes/This attribute/ s3 in 'grouping oms-element: elt-index': s/allowing to sort/allowing the sorting/ s3 in 'container transponders: list transponder:leaf termination-type-capabilities: enum 3r-or-tunnel:" s/can be configure/can be configured/ s3 in 'container transponders:list transceiver:leaf explicit-transceiver-mode-ref:" s/The refernce to the explicit/The reference to the explicit/ s3 in 'container transponders:container regen-groups:leaf regen-metric:' s/among different group/among different groups/ s3 in 'container transponders:container regen-groups:leaf-list transponder-ref:' s/The list of transponder/The list of transponders/ Appendix B: There does not appear to be a reference to Appendix B in the body of the document. I would have expected that there would have been a pointer to it somewhere!