Re: [yang-doctors] Yangdoctors Early Review of draft-ietf-lpwan-schc-yang-data-model-04

[Laurent Toutain <[e-mail]>]

Dear Carl and Mehmet,

Thank you very much for your review and all the advice, this will help us
to have a better document. I'm quite new in YANG and I was not aware of the
--ietf argument. It reports a lot of errors, I will correct them. -f yang
is also an option I was looking for to have more readable documents.

Regarding the FID, you are right, it is too flat right now, we will change
it to have something more hierarchical that allows also to go inside a
field to allow subfields ids.

For the last point, how do you establish a relation between fields in a
yang model?

Thank you again for your help

Laurent

On Sun, Apr 18, 2021 at 5:16 PM Mehmet Ersue <[e-mail]> wrote:

> I’m sending this on behalf of Carl Moberg.
>
> It seems there was an issue and the review mail has not been generated.
>
> Text copied from
>
>
> https://datatracker.ietf.org/doc/review-ietf-lpwan-schc-yang-data-model-04-yangdoctors-early-moberg-2021-04-13/
>
>
>
> Mehmet
>
>
>
> Reviewer: Carl Moberg
>
> Review result: On the Right Track
>
>
>
> This is my YANG Doctors Early Review of
> draft-ietf-lpwan-schc-yang-data-model-04
>
>
>
> It is obviously challenging to provide early review feedback on how useful
> and efficient the YANG model representation is for a set of technologies
> that I am not an expert on, but here goes.
>
>
>
> Understanding that it is still early in the lifecycle of the module, I
> have not spent time on providing feedback on e.g. description texts,
> capitalization and spelling but have focused on the general structure and
> design of the module. I also haven't spent any time dissecting the output
> of `pyang --ietf`, but I would suggest the authors start looking into that
> as the content of the module moves ahead towards publication.
>
>
>
> I would also suggest considering running the module through `pyang -f
> yang` as that provides nice and consistent formatting and quoting.
>
>
>
> As for the content itself. I believe to the best of my understanding that
> the YANG module reflects the core data structures of RFC8724 well. I have a
> couple of questions that may lead to broader discussion on _how_ to capture
> certain aspects of these data structures in a way that makes it realistic
> to implement while still easy to use.
>
>
>
> As is right now, the YANG module assumes that all implementations support
> all FID types defined to be derived from field-id-base-type. It includes
> fields related IPv6, COAP/OSCORE, and ICMPv6 all in the same module. Is
> there a possibility that some implementations won't implement all three of
> those protocol groups? If so, it might be worth considering making FID type
> groups either optional using YANG 'feature' statements or break them out
> into separate modules to be advertised separately.
>
>
>
> There is currently no correlation between field-id type and field-length
> types in the same compression rule entry. I.e. the current YANG permits a
> field-identifier 'fid-ipv6-version' combined with a field-length
> 'fl-token-length' in a rule entry, which I understand to be nonsensical. If
> I am right in that it's an example of meaningless configuration, does the
> authors think it important (and possible) to work towards a more stringent
> validation of "meaningful" configuration by capturing the relationships
> between fields like in this example?
>
>
>
>
>