Re: [Roll] RtgDir Review: draft-ietf-roll-unaware-leaves-23

["Pascal Thubert (pthubert)" <[e-mail]>]

Many thanks Julien!

I guess we are getting ready for RFC editor process; I made the changes in the repo and published -30 for your convenience:
https://www.ietf.org/rfcdiff?url2=draft-ietf-roll-unaware-leaves-30

Please note that we already had changed section 12.6 based on a suggestion by IANA. 
I modified as follows:
"
12.6.  New Subregistry for RPL Rejection Status values

   This specification creates a new Subregistry for the RPL Rejection
   Status values for use in the RPL DAO-ACK and DCO messages with the
   'A' flag set to 0, under the RPL registry.

   *  Possible values are 6-bit unsigned integers (0..63).

   *  Registration procedure is "IETF Review" [RFC8126].

   *  Initial allocation is as indicated in Table 5:

    +--------------------+-----------------------+-------------------+
    | Value              | Meaning               | Reference         |
    +--------------------+-----------------------+-------------------+
    | 0                  | Unqualified rejection | THIS RFC          |
    +--------------------+-----------------------+-------------------+
    | 1 (suggested in    | No routing entry      | [EFFICIENT-NPDAO] |
    | [EFFICIENT-NPDAO]) |                       |                   |
    +--------------------+-----------------------+-------------------+
    | 2..63              | Unassigned            |                   |
    +--------------------+-----------------------+-------------------+

               Table 5: Rejection values of the RPL Status
" 

Take care,

Pascal

> -----Original Message-----
> From: [e-mail] <[e-mail]>
> Sent: jeudi 21 janvier 2021 18:38
> To: Pascal Thubert (pthubert) <[e-mail]>
> Cc: [e-mail]; [e-mail]; [e-mail]; draft-ietf-roll-unaware-
> [e-mail]
> Subject: Re: RtgDir Review: draft-ietf-roll-unaware-leaves-23
> 
> Salut Pascal.
> 
> Sorry for the late feedback. For the sake of following-up, your
> responses and I-D updates address my concerns.
> 
> Please consider the following few nits.
> 
> A missing coma and a typo in section 4.2.2:
> OLD
>    This is the reason why the support
>    of [RFC8505] by the RUL, as opposed to only [RFC6775] is a
>    prerequisite for this specification)/; this requirement is fully
>    explained in Section 5.1.
> NEW
>    This is the reason why the support
>    of [RFC8505] by the RUL, as opposed to only [RFC6775], is a
>    prerequisite for this specification; this requirement is fully
>    explained in Section 5.1.
> 
> In section 11: s/the overusing that channel/overusing that channel/  [or
> "the overuse of that channel"]
> 
> In Table 5 of section 12.6, the allocation for the [EFFICIENT-NPDAO]
> work-in-progress should rather be referred to as "to be defined".
> 
> Thanks,
> 
> Julien
> 
> 
> On 18/12/2020 15:11, Pascal Thubert (pthubert) wrote:
> > Salut Julien:
> >
> > Many thanks for your review!
> >
> > I committed the changes that I understood in https://github.com/roll-
> wg/roll-unaware-
> leaves/commit/d029d605fe4dbfa2ff1c444210fa67f923b715e4
> >
> > For your convenience, I also published an update for you to visualize the
> changes:
> > Htmlized:       https://tools.ietf.org/html/draft-ietf-roll-unaware-leaves-28
> > Diff:           https://www.ietf.org/rfcdiff?url2=draft-ietf-roll-unaware-leaves-
> 28
> >
> > Please let me know if there is more to be done.
> >
> > For the deep review discussion, please see below.
> >
> >> *Comments:*
> >>
> >> I am not an LLN expert, but I find the I-D convenient to read thanks to the
> >> appropriate (but numerous) references. I just feel that a few sections
> deserve
> >> some clarification to improve readability and that flag number selection
> >> doesn't really follow the expected process.
> > Cool, let's see how we can make things (even 😉) better.
> >
> >
> >> *Minor Issues:*
> >>
> >> - Sorry if ask questions on implicit contexts that are obvious to LLN people,
> >> but I am confused in section 3 with that "6LR that acts as a border Router
> for
> >> external routes": does it advertise towards the RPL domain? Does it talk to
> a
> >> peer 6LR that is also a RPL Router? Is that particular router necessarily the
> RPL
> >> Root?
> > There were similar comments and I already made some changes:
> > 1) added a picture that hopefully helps here
> >
> >          ------+---------
> >                |          Internet
> >                |
> >             +-----+
> >             |     | &lt;------------- 6LBR / RPL Root
> >             +-----+                     ^
> >                |                        |
> >          o    o   o  o                  | RPL
> >      o o   o  o   o  o     o    o       |
> >     o  o o  o o    o   o  o   o  o      |  +
> >     o   o      o     o   o   o    o     |
> >    o  o   o  o   o  o    o    o  o      | 6LoWPAN ND
> >       o  o  o  o        o   o           |
> >      o       o            o    o        v
> >    o      o     o <------------- 6LR / RPL Border router
> >                                         ^
> >                                         | 6LoWPAN ND only
> >                                         v
> >                 u <------------- 6LN / RPL-Unaware Leaf
> >
> >
> > To clarify more I changed section 3 as follows:
> > "
> > 3.  RPL External Routes and Dataplane Artifacts
> >
> >    RPL was initially designed to build stub networks whereby the only
> >    border router would be the RPL Root (typically collocated with the
> >    6LBR) and all the nodes in the stub would be RPL-Aware.  [RFC6550]
> >    has the provision of external routes with the External 'E' flag in
> >    the Transit Information Option (TIO).  External Routes enable to
> >    reach destinations that are outside the RPL domain and connected to
> >    the RPL domain via RPL border routers that are not the route.
> >    Section 4.1 of [USEofRPLinfo] provides a set of rules summarized
> >    below that must be followed for routing packets from and to a
> >    external destinations (targets in RPL parlance).  A RUL is a special
> >    case of external target that is also a host directly connected to the
> >    RPL domain.
> > "
> >
> > Does that help?
> >
> >> - The text in section 6.2, as well as figures 3 and 4, use the F and P flags as
> if
> >> the bit numbers were defined, though their number is only "suggested" in
> the
> >> IANA section. If no early allocation process happened, it is inappropriate
> to
> >> assume the to-be-allocated bit number in the body of the document.
> > At this stage, we already made a pass with Amanda Baber (IANA).
> > A change would be pure form to be undone by the RFC editor.
> >
> >> - Section 6.3 reduces an 8-bit field to a 6 bit value. It would be worth
> >> mentioning that it sounds reasonable because the associated registry
> relies
> >> on standards action for registration and only values up to 10 are currently
> >> allocated.
> > Good point; done.
> >
> >> Furthermore, is there an update of that 6-bit space split to map the
> previous
> >> ranges? If the answer lies in the IANA section, then a few words would be
> >> welcome in section 6.
> > Aïe, I do not understand the question. We used to map 1 to 1 the ND status
> to RPL status, but after a discussion with Alvaro we found that embedding
> was better.
> >
> >
> >> *Nits:*
> >> ------
> >> Overall
> >> ---
> >> - RPL-[An]aware, RAL and RUL are preceded most of the times by "a" [OK
> if
> >> pronounced "riple", "ral", "rul"], but sometimes by "an" ["are
> >> pi..."]: please pick one and be consistent.
> > Done. We say a RPL, a RUL, a RAL, and an RPI.
> >
> >> - Any reason why "Host", "Hop" and "Router" are often written with a
> capital
> >> H/R?
> > Hum I thought I cleaned that up for the most part. Doing another pass I do
> not find much.
> > I use the uppercase on Hop-by-Hop because that is what RFC 8200 does.
> Same for 6LBR, 6LR, 6BBR, etc... else I used lowercase
> >
> >
> >> - RFC 2119 keywords SHOULD be used more often for an IETF standard
> track,
> >> it sometimes feels that the text is written to circumvent them.
> >> E.g., section 4.2.1 uses a wording based on "requires... if and only if...";
> >> section 4.3 describes a behavior without any normative keyword; section
> 5.1
> >> says "needs to", "is expected not to", "is suggested to"; etc.
> > There's more here than meet the eye. Remember that we extend existing
> work in RPL, ND and IPv6. The reason for the wording is that the MUST or
> SHOULD is already written in an RFC and we do not want to paraphrase std
> track text here.
> >
> >> ------
> >> Section 1.
> >> ---
> >> - The phrase "terminate packets" feels odd: is "terminate paths"
> intended?
> > This is gone already
> >
> >> - s/expectations/requirements/
> > Done
> >
> >> - The term "change" is used several times in the section summary though
> it is
> >> a bit loose: depending on the situation, "modify" or "extend"
> > There's both; we actually are more specific in the sections. I found one
> place where I did a replacement.
> >
> >
> >> would be more specific (the former may impact existing implementations,
> the
> >> latter does not).
> > Yes this is when we use "update".
> >
> >> -  OLD
> >>       Section 8 presents the changes made to [RFC6775] and [RFC8505];
> >>       The range of the ND status codes is reduced down to 64 values, and
> >>       the remaining bits in the original status field are now reserved.
> >>   NEW
> >>       Section 8 presents how [RFC6775] and [RFC8505] are used; the
> >>       range of the ND status codes is narrowed down to 64 values, and
> >>       the unused bits are reserved.
> > This was the goal when I wrote RFC 8505. I missed tiny things and had to
> perform updates which are listed in " Enhancements to RFC 6775 and
> RFC8505". Because of that this document updates RFC 6775 and 8505. Sadly.
> >
> >> ------
> >> Section 2.
> >> ---
> >> - s/Neighbor solicitation/Neighbor Solicitation/
> > Done
> >
> >> - s/Information solicitation (DIS)/Information Solicitation (DIS)/
> > Removed
> >
> >> ------
> >> Section 3.
> >> ---
> >> - s/The RPL Root tunnels the packets/The RPL Root tunnels data packets/
> >> [unless we're talking about control packet]
> > Done
> >
> >> - s/forwards the original (inner) packet/forwards original (inner) packets/
> > Done
> >
> >> ------
> >> Section 4.
> >> ---
> >> - s/Neighbor solicitation (NS)/Neighbor Solicitation (NS)/
> > Done
> >
> >> - s/6LN functionality in [RFC8505]/6LN functionality from [RFC8505]/
> > Done though unconvinced. Let's see what the RFC editor ends up doing.
> >
> >> - Section 4.2.3 summarizes the main use case of the ROVR though its use
> here
> >> is a bit different: why not focus the paragraph on the latest sentence and
> >> bring a correct topic balance into the section?
> > This section describes RFC 8505. It hints about how we use it in the rest of
> the spec but that's not the main goal.
> >
> >
> >> ------
> >> Section 5.
> >> ---
> >> - s/with a CIO/with a 6CIO/
> > Done
> >
> >> - s/the Root terminates the IP-in-IP tunnel at the parent 6LR/the IP-in-IP
> >> tunnel from the Root terminates at the parent 6LR/
> > Done
> >
> >> ------
> >> Section 6.
> >> ---
> >> - s/between the 6LR and the RPL Root/between the RPL Root and the 6LR/
> > In both directions in fact
> >
> >> - s/encodes it in one of these reserved flags of the RPL DODAG
> configuration
> >> option/allocates a new one in the RPL DODAG configuration option/
> > That sentence was reworded since -23. But the allocation game is for IANA
> section. Arguably  what matters to the implementer is the bit position.
> >
> >> - s/values zero (0) to six (6)/values from zero (0) to six (6)/
> > Done
> >
> >> ------
> >> Section 7.
> >> ---
> >> - The section title should point to the draft title ("Efficient Route
> >> Invalidation") rather than the draft name which will be replaced by an RFC
> >> number at publication time.
> > Point is, both drafts will publish together and this is to help the editor to
> the replacements.
> >
> >> - s/hop by hop/hop-by-hop/
> > Done
> >
> >> ------
> >> Section 8.
> >> ---
> >> - Spacing inconsistency on the section title.
> > Fixed
> >
> >> ------
> >> Section 9.
> >> ---
> >> - In section 9.2.2, the capital T is missing on "the" for steps 4 and 5.
> > Fixed
> >
> >> - s/Lifetime. e.g./Lifetime. E.g./
> > Fixed
> >
> >> - s/6LoWPAN ND related reasons/6LoWPAN ND-related reasons/
> > Fixed
> >
> >> - s/An error injecting the route/An error when injecting the route/
> > Not sure; since several native speakers reviewed it I'd rather leave this as is
> >
> >> - In section 9.2.3, the capital T is missing on "the" for steps 2 and 3.
> > Fixed
> >
> >> ------
> >> Section 11.
> >> ---
> >> - s/supporting th extension/supporting the extension/
> > Fixed
> >
> >> ------
> >> Section 12.
> >> ---
> >> - s/doesn't/does not/
> > Fixed
> >
> >> ------
> >>
> >>
> >> Regards,
> >>
> >> Julien
> >>
>