Early Review of draft-ietf-mpls-spring-inter-domain-oam-05
review-ietf-mpls-spring-inter-domain-oam-05-rtgdir-early-richardson-2023-06-28-00
review-ietf-mpls-spring-inter-domain-oam-05-rtgdir-early-richardson-2023-06-28-00
RtgDir Early review: draft-ietf-mpls-spring-inter-domain-oam-05 Hello I have been selected to do a routing directorate “early” review of this draft. https://datatracker.ietf.org/doc/draft-foo-name/ The routing directorate will, on request from the working group chair, perform an “early” review of a draft before it is submitted for publication to the IESG. The early review can be performed at any time during the draft’s lifetime as a working group document. The purpose of the early review depends on the stage that the document has reached. <case 1> As this document has recently been adopted by the working group, my focus for the review is on providing a new perspective on the work, with the intention of catching any issues early on in the document's life cycle. For more information about the Routing Directorate, please see http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir Document: draft-ietf-mpls-spring-inter-domain-oam-05 Reviewer: Michael Richardson Review Date: 2023-06-28 Intended Status: Standards Track Summary: I have some minor concerns about this document that I think should be resolved before it is submitted to the IESG. I think that most of the mechanism is probably obvious to those steeped in SRv6 and modern MPLS. I complain below about lots of small issues, but the document is basically ready. Comments: Is RFC7743 widely implemented, or does the difficulty of slow path processing make it completely impractical? Is this document likely to replace 7743, or if there was no 7743 deployment, why is this document more likely to deployed? "The TLV can either be derived by a smart application or controller which has a full topology view. " but in the multi-AS case, is there any controller which actually has a view of topologies in all ASes? 1.1's definition of domain seems rather intricate as to when it applies, and I wonder if a negative example might help solidify when this can and cannot be used. "One of the ways this can be implemented on headend is to acquire the entire database (of all domains) and build return path for every node along the SR-MPLS path based on the knowledge of the database. " But, if the headend knows all the connectivity, why do we need traceroute at all? I found the rules in section 6.2 to be hard to read. I didn't find section 7.1 useful as an example, as it wasn't specific enough. 7.2: "When echo request reaches ASBR1, and echo reply is received, the next echo request needs to include additional label as ASBR1 is a border node." It's unclear how the headend knows it has reached ASBR1. Please split the two examples (PE1->PE4) from the PE1->PE5 example in different sections so that they be referred to easier. I am not sure if the proceedure in 8.1 is really normative, or just an example of one proceedure. I found the use of "MUST" here not useful. I think that the intention of text like: The Reply Path TLV MUST consist of its own node label and an EPE-SID to the AS from where the traceroute message was received. Is really, that it is saying that a Reply Path TLV that includes its own node label allows an EPE-SID to know where the traceroute was received. I.e. it's not that any of it is "MUST", in the sense that the packet is invalid if it's not there, but rather, in order to be useful something specific needs to be done. Perhaps some future use of these facilities will find other ways to organize the TLVs, those packets are not invalid (and need to be discarded), but rather may have other utility. section 8.2 is begging to just be a time-sequence diagram. I didn't find the Security Considerations useful. summary: "Don't let bad packets in" While it should say, "If bad packets get in, then this is what they can do" Please supply an overview of the draft quality and readability. Include any issues you've spotted, and whether you think these are major blocking issues or comments about clarity or technical accuracy. Include any questions you have on points that are unclear or seem ambiguous. Include anything else that you think will be helpful toward understanding your review. Give as much context information as possible with your comments (e.g., section numbers, paragraph counts). Nits: s/facilitae/facilitate/