Re: [mpls] Review of draft-ietf-mpls-residence-time-122017-01-19 10:01:10Hi Les, I believe that IGP extensions to advertise RTM capability are required. Regards, Greg On Thu, Jan 19, 2017 at 7:57 AM, Les Ginsberg (ginsberg) <ginsberg(_at_)cisco(_dot_)com wrote: Greg – I am having trouble understanding your response. The question we are raising is whether we should extend the IGPs to support advertising RTM capability – an alternative being to retrieve the capability via network management. Saying that the IGP functionality is optional and/or wouldn’t always be advertised doesn’t really answer the question of whether we should or should not define the IGP extensions. Could you respond more directly to this point? Les *From:* Greg Mirsky [mailto:gregimirsky(_at_)gmail(_dot_)com] *Sent:* Thursday, January 19, 2017 7:44 AM *To:* Acee Lindem (acee) *Cc:* Robert Sparks; mpls(_at_)ietf(_dot_)org; gen-art(_at_)ietf(_dot_)org; draft-ietf-mpls-residence-time(_dot_)all(_at_)ietf(_dot_)org; ietf(_at_)ietf(_dot_)org; Les Ginsberg (ginsberg); isis-chairs(_at_)ietf(_dot_)org; Abhay Roy (akr) *Subject:* Re: [mpls] Review of draft-ietf-mpls-residence-time-12 Hi Acee, the draft defines optional functionality. If an operator has no use neither for PTP's Transparent Clock, nor RTM itself as performance metric, then RTM sub-TLV would not be included and thus it would not be flooded. Of course, it be right to reflect RTM capability through YANG data model, thus allowing SDN scenario you've described. Regards, Greg On Wed, Jan 18, 2017 at 2:51 PM, Acee Lindem (acee) <acee(_at_)cisco(_dot_)com> wrote: Hi Greg, Although it is a bit late, we’ve had some discussions amongst the IS-IS and OSPF chairs and are wondering whether the interface capability belongs in the IGPs. This will be flooded throughout the entire routing domain – is it really needed on every node or will it the RTM testing be initiated from an omniscient NMS client that would know the capabilities of each node or easily query them using YANG? Thanks, Acee *From: *mpls <mpls-bounces(_at_)ietf(_dot_)org> on behalf of Greg Mirsky < gregimirsky(_at_)gmail(_dot_)com> *Date: *Wednesday, January 18, 2017 at 1:25 PM *To: *Robert Sparks <rjsparks(_at_)nostrum(_dot_)com> *Cc: *"mpls(_at_)ietf(_dot_)org" <mpls(_at_)ietf(_dot_)org>, "gen-art(_at_)ietf(_dot_)org" < gen-art(_at_)ietf(_dot_)org>, "draft-ietf-mpls-residence-time(_dot_)all(_at_)ietf(_dot_)org" < draft-ietf-mpls-residence-time(_dot_)all(_at_)ietf(_dot_)org>, "ietf(_at_)ietf(_dot_)org" < ietf(_at_)ietf(_dot_)org> *Subject: *Re: [mpls] Review of draft-ietf-mpls-residence-time-12 Hi Robert, thank you for the most expedient review and comments. I'll make changes in Section 2 per your suggestion. Regards, Greg On Wed, Jan 18, 2017 at 10:34 AM, Robert Sparks <rjsparks(_at_)nostrum(_dot_)com> wrote: The changes all look good. I still think you should say something in the document about what "the time of packet arrival" and "transmission" means, and call out the point you made about being careful to not introduce apparent jitter by not making those measurements consistently. (The definitions you point to in your earlier mail from G.8013 don't really help - they just say "time of packet arrival". Again, the first and last bit are likely to be several nanoseconds apart so I think it matters. Perhaps you're saying it doesn't matter as long as each node is consistent (there will be error in the residence time measurement, but it will be constant at each node, so the sum of errors will be constant, and the clocks will be ok?) Please look at the new first paragraph of section 2 - there's a mix of "as case" and "in case" that should be made consistent. I suspect it would be easiest to simply say "referred to as using a one-step clock" and "referred to as using a two-step clock" or similar. RjS On 1/18/17 12:03 PM, Greg Mirsky wrote: Hi Robert, Sasha Vainshtein came with elegant idea to address disconnection between discussion of one-step and two-step modes that you've pointed out. We've moved Section 7 as sub-section into Section 2 now. Attached are updated diff and the proposed new version -13. Regards, Greg On Wed, Jan 18, 2017 at 8:13 AM, Greg Mirsky <gregimirsky(_at_)gmail(_dot_)com> wrote: Hi Robert, once again, thank you for your thorough review and the most detailed comments. I've prepared updated version and would greatly appreciate if you review the changes and let us know whether your comments been addressed. Attached are diff and the new version. Regards, Greg On Wed, Jan 11, 2017 at 7:48 AM, Robert Sparks <rjsparks(_at_)nostrum(_dot_)com> wrote: Reviewer: Robert Sparks Review result: Ready with Nits 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 <https://trac.ietf.org/trac/gen/wiki/GenArtfaq>. Document: draft-ietf-mpls-residence-time-12 Reviewer: Robert Sparks Review Date: 2017-01-10 IETF LC End Date: 2017-01-17 IESG Telechat date: 2017-02-02 Summary: Ready (with nits) for publication as a Proposed Standard I have two primary comments. I expect both are rooted in the authors and working group knowing what the document means instead of seeing what it says or doesn't say: 1) The document is loose with its use of 'packet', and where TTLs appear when they are discussed. It might be helpful to rephrase the text that speaks of RTM packets in terms of RTM messages that are encoded as G-ACh messages and not refer to packets unless you mean the whole encapsulated packet with MPLS header, ACH, and G-ACh message. 2) Since this new mechanic speaks in terms of fractional nanoseconds, some discussion of what trigger-point you intend people to use for taking the precise time of a packet's arrival or departure seems warranted. (The first and last bit of the whole encapsulated packet above are going to appear at the physical layer many nanoseconds apart at OC192 speeds if I've done the math right). It may be obvious to the folks discussing this, but it's not obvious from the document. If it's _not_ obvious and variation in technique is expected, then some discussion about issues that might arise from different implementation choices would be welcome. The rest of these are editorial nits: It would help to pull an overview description of the difference between one-step and two-step much earlier in the document. I suggest in the overview in section 2. Otherwise, the reader really has to jump forward and read section 7 before section 3's 5th bullet makes any sense. In section 3, "IANA will be asked" should be made active. Say "This document asks IANA to" and point to the IANA consideration section. Apply similar treatment to the other places where you talk about future IANA actions. There are several places where there are missing words (typically articles or prepositions). You're less likely to end up with misinterpretations during the RFC Editor phase if you provide them before the document gets that far in the process. The spots I found most disruptive were these (this is not intended to be exhaustive): Section 3: "set 1 according" -> "set to 1 according" Section 3: "the Table 19 [IEEE..." -> "Table 19 of [IEEE..." Section 4.2: "Detailed discussion of ... modes in Section 7." -> "Detailed discussion of ... modes appears in Section 7." Section 10: "most of" -> "most of all" In Setion 3.1 at "identity of the source port", please point into the document that defines this identity and its representation. I suspect this is a pointer into a specific section in IEEE.1588.2008].
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