Re: [Last-Call] RtgDir Last Call review: draft-ietf-dots-telemetry-use-cases-12

[H Y <[e-mail]>]

Hi,

Thank you for your careful review.

We have submitted the draft 13 to address your comments.
Diff is here.
https://www.ietf.org/rfcdiff?url2=draft-ietf-dots-telemetry-use-cases-13

Please see inline.

>Hello,
>
>I have been selected as the Routing Directorate reviewer for this draft. The Routing Directorate seeks to review all ro>uting or routing-related drafts as they pass through IETF last call and IESG review, and sometimes on special request. >The purpose of the review is to provide assistance to the Routing ADs. For more information about the Routing Directora>te, please see http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir
>
>Document: draft-name-version
>Reviewer: Donald Eastlake 3rd
>Review Date: 2 October 2022
>Intended Status: Informational
>
>Summary:
>I have some minor concerns about this document that I think should be resolved before publication.
>
>Comments:
>This is a reasonably straightforward Informational document giving examples of the use of DOTS Telemetry, as specified >in RFC 9244, to improve the efficiency of DDoS mitigation. It is quite readable but I found the text to be somewhat ver>bose and repetitive.
>
>Major Issues:
>No major issues found.
>
>Minor Issues:
>
>Section 3.1.1, page 6: If the point is that some DMSes have limited capacity, then shouldn't directing "as much of the >top-talker's traffic to the DMS as possible" by "directing as much of the top-talker's traffic to each DMS as that DMS >can handle" or the like?
[Yuhei]
We addressed the comment.

OLD:
After that, the orchestrator orders the forwarding nodes to redirect
as much of the top-talker's traffic to the DMS as possible by
dissemination of Flow Specifications using tools such as Border
Gateway Protocol Dissemination of Flow Specification Rules (BGP
Flowspec) [RFC8955].

NEW:
After that, the orchestrator orders the forwarding nodes to redirect
as much of the top-talker's traffic to each DMS as that DMS can handle
by dissemination of Flow Specifications using tools such as Border
Gateway Protocol Dissemination of Flow Specification Rules (BGP
Flowspec) [RFC8955].

>
>Why is only SNMP mentioned in this document and not YANG?
[Yuhei]
We addressed the comment.

Of course, YANG/NETCONF can be used as an alternative to SNMP.
We modified the sentence below and some figures.

OLD:
such as Simple Network Management Protocol (SNMP) [RFC3413].

NEW:
such as Simple Network Management Protocol (SNMP) [RFC3413] or YANG
with Network Configuration Protocol (YANG/NETCONF) [RFC6020].

>
>Nits:
>
>I am suspicious of the heavy use of the word "optimal" in this document. I did not see any place where the criterion or> metric for optimality is defined nor did I see any demonstration that the example uses provide optimal mitigation tech>niques. But it is hard to blame the authors of this draft when the Standards Track RFC 9244 on which these examples are> based has the same problem. If it were not for the use of "optimal" in RFC 9244, I would have counted this as a Minor >Issue.
>
>For example, Section 3.1.2, page 8, asserts that, based on DOTS telemetry information, "the orchestrator selects an opt>imal DMS". It then gives as an example a very simple selection algorithm which I might describe as selecting an "adequa>te" DMS. Then in the following one-sentence paragraph, it says the selection algorithm is out of scope. How can it be a>sserted that an optimal DMS will be selected without giving any hint as to how to find an algorithm to make such an opt>imal choice? Similar comments would apply to other Sections of this document.

[Yuhei]
In the RFC 9244, some "optimal" words exist.
However, as you are concerned, we should explain the "optimal" more
specifically.
In addition, the same things can be said about "Best".

We removed the "optimal" and "best" word from all the documents except
the introduction.
We also add some words to explain more specifically.

Section 3.1.2
OLD:
This use case enables transit providers to select an optimal DMS for
mitigation based on the volume of the attack traffic and the capacity
of a DMS.

NEW:
This use case enables transit providers to select an DMS with
sufficient capacity for mitigation based on the volume of the attack
traffic and the capacity of a DMS.

Section  3.1.3
OLD:
This use case enables transit providers to select an optimal path for
redirecting attack traffic to a DMS according to the bandwidth of the
attack traffic and total traffic.

NEW:
This use case enables transit providers to select an path with
sufficient bandwidth for redirecting attack traffic to a DMS according
to the bandwidth of the attack traffic and total traffic.

>
>Section 3.1.5: "based on the" -> "based on the"
[Yuhei]
We addressed the comment.

>
>Sections 4 and 9: There seems to be a dangling "Thanks to" at the end of Section 9. The last line of Section 4 seems to> be an acknowledgement which should, perhaps, be in Section 9.
[Yuhei]
Oops.
We addressed the commnet.

>
>Adding a reference for "DNS Water Torture Attack" would be good.
[Yuhei]
We addressed the comment.

>
>Suggest deleting both occurrences of "In particular".
[Yuhei]
We addressed the comment.

>
>Thanks,
>Donald



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Yuuhei HAYASHI
08065300884
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