Re: [mpls] Review of draft-ietf-mpls-residence-time-12

[Greg Mirsky <[e-mail]>]

Hi 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) <[e-mail]
> 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:[e-mail]]
> *Sent:* Thursday, January 19, 2017 7:44 AM
> *To:* Acee Lindem (acee)
> *Cc:* Robert Sparks; [e-mail]; [e-mail];
> [e-mail]; [e-mail]; Les Ginsberg
> (ginsberg); [e-mail]; 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) <[e-mail]>
> 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 <[e-mail]> on behalf of Greg Mirsky <
> [e-mail]>
> *Date: *Wednesday, January 18, 2017 at 1:25 PM
> *To: *Robert Sparks <[e-mail]>
> *Cc: *"[e-mail]" <[e-mail]>, "[e-mail]" <
> [e-mail]>, "[e-mail]" <
> [e-mail]>, "[e-mail]" <
> [e-mail]>
> *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 <[e-mail]>
> 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 <[e-mail]>
> 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 <[e-mail]>
> 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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