Re: [Int-dir] Intdir telechat review of draft-ietf-tvr-use-cases-05

[Yingzhen Qu <[e-mail]>]

Hi Pascal,

Would you please check whether your comments have been addressed?

Thanks,
Yingzhen

On Sat, Feb 24, 2024 at 3:58 PM Yingzhen Qu <[e-mail]> wrote:

> Hi Pascal,
>
> Thanks for the review and comments. Please see my answers below.
>
> Thanks,
> Yingzhen
>
> On Wed, Feb 21, 2024 at 8:43 AM Pascal Thubert via Datatracker <
> [e-mail]> wrote:
>
>> Reviewer: Pascal Thubert
>> Review result: Ready with Issues
>>
>> I am an assigned INT directorate reviewer for draft-ietf-tvr-use-cases
>> (05).
>> These comments were written primarily for the benefit of the Internet Area
>> Directors. Document editors and shepherd(s) should treat these comments
>> just
>> like they would treat comments from any other IETF contributors and
>> resolve
>> them along with any other Last Call comments that have been received. For
>> more
>> details on the INT Directorate, see
>> https://datatracker.ietf.org/group/intdir/about/
>> <https://datatracker.ietf.org/group/intdir/about/>."
>>
>> For non-INT Area document, the reviewer must give a recommendation as to
>> how
>> the INT ADs are to complete the ballot on the document and the reason for
>> that
>> recommendation.
>>
>> I believe that the document is very well written and highly readable.
>>
>> My comments may be seen as a matter of taste and ignored, or/and be
>> considered
>> out of scope.
>>
>> My main concern is that despite a "Routing Impacts" subsection in all main
>> groups of use cases, there's no text on the scope of routing impact.
>>
>> - Is the impact local like FRR in which case it can be understood?
>> - Or is it more global in which cases the impact is harder to assess in
>> advance? - flows may be rerouted paths that are loaded differently from
>> the
>> original, meaning that there's a measurable impact at the time of the
>> switch,
>> for the better or the worse - How, when can the impact be gradual? - Is
>> the
>> impact a complete reroute of the flow or a variation of the load
>> balancing?
>>
>> Background fo rthe questions: Rick and myself have a strong RAW
>> background.
>> Contrary to the examples given (and the WG ovbjectives), RAW is reactive
>> (OAM
>> based); but once a decision is made, it seems that the RAW methods are
>> applicable in certain listed use cases and may provide a smpooth solution
>> to
>> the local TVR use cases.
>>
>> Related comment is that the "Routing Impacts" subsections are not
>> comparable
>> from one use case to the other. Again I'd have loved comparable items
>> like the
>> above to be discussed so we figure if we are looking for common or
>> separate
>> solutions.
>>
>> [Yingzhen]: As we know, Fast Reroute (FRR) is a local mechanism designed
> to handle unexpected node or link failures, and there might be policies for
> determining which traffic should be switched to the backup path. However,
> this falls outside the scope of TVR's charter and this document. Scheduled
> maintenance, such as link shutdowns, is within scope. Ultimately, how
> routing protocols handle these scheduled events is up to the protocols,
> including deciding whether a 'one size fits all' solution is appropriate.
> One of the objectives of the use case document is to clarify the cases
> considered by TVR.
>
> Secondary, on :
>>                                 "To the extent that the relative mobility
>>                                 between and among nodes in the network
>> can be
>>                                 understood in advance, the associated
>> loss and
>>                                 establishment of adjacencies can also be
>>                                 planned for."
>>
>> This is clearly discussing radios. Most radios use cases depend not only
>> on the
>> relative position, but also the rest of the environment that may obstruct
>> and /
>> or interfere with the signal. Suggestion:
>>
>>                                 "To the extent that the relative mobility
>>                                 between and among nodes in the network
>> and the
>>                                 impacts of the environment on the signal
>>                                 propagation can be understood in advance,
>> the
>>                                 associated loss and establishment of
>>                                 adjacencies can also be planned for."
>>
>> [Yingzhen]: thanks for the suggested text. I've published version -06
> with the suggested changes.
>
>
>> Many thanks again for this document, great and informational read
>>
>>
>