Re: [Idr] Lars Eggert's No Objection on draft-ietf-idr-rfc7752bis-14: (with COMMENT)

[Ketan Talaulikar <[e-mail]>]

Hi Lars,

What we have in the latest version (posted earlier today) is the following:
https://datatracker.ietf.org/doc/html/draft-ietf-idr-rfc7752bis-15#section-5.1

   To compare NLRIs with unknown TLVs, all TLVs within the NLRI MUST be
   ordered in ascending order by TLV Type.  If there are multiple TLVs
   of the same type within a single NLRI, then the TLVs sharing the same
   type MUST be first in ascending order based on the length field
   followed by ascending order based on the value field.  Comparison of
   the value fields is performed by treating the entire field as opaque
   binary data and ordered lexicographically.


Does that work?

Thanks,
Ketan


On Fri, Feb 17, 2023 at 5:33 PM Lars Eggert <[e-mail]> wrote:

> Hi,
>
> On Feb 17, 2023, at 13:54, Ketan Talaulikar <[e-mail]> wrote:
> > > ```
> > >      To compare NLRIs with unknown TLVs, all TLVs within the NLRI MUST
> be
> > >      ordered in ascending order by TLV Type.  If there are multiple
> TLVs
> > >      of the same type within a single NLRI, then the TLVs sharing the
> same
> > >      type MUST be in ascending order based on the value field.
> Comparison
> > >      of the value fields is performed by treating the entire field as
> > >      opaque binary data and ordered lexicographically.
> > > ```
> ...
> > KT2> Are you suggesting that the description in the text is
> insufficient? I am not sure if a Wikipedia article would fly as a (in this
> case normative?) reference.
>
> Yes, I think you need to say something more, because the current text says
>
> 1. order TLVs by type
> 2. if there are multiple TLVs of the same type, order them by value
> 3. to order by value, order lexicographically
>
> My point is that in step 3, the values may be of different lengths, and so
> you need to say what *kind* of lexicographic order you intend (= shortlex).
>
> You don't need to cite Wikipedia, you could also just require that values
> are first compare solely by length and lexicographically when the lengths
> are equal.
>
> Lars
>