Re: [netmod] [core] js review of draft-ietf-core-yang-cbor-12

[Juergen Schoenwaelder <[e-mail]>]

On Wed, Apr 08, 2020 at 01:55:47PM +0200, Carsten Bormann wrote:
> >> Ha.
> >> 
> >> Let’s create a registry in yang-cbor for id= values (initially filled with id=name).
> >> -sid can then register id=sid in that.
> > 
> > He? yang-cbor defines how to use sids as ids so I see no reason to not
> > also register the id=sid in yang-cbor. I thought we settled on
> > yang-cbor defines what sids are and the sid id details how they are
> > assigned and how the number space is managed. This way, yang-cbor is
> > the base document and the sid document has a normative reference to
> > yang-cbor and comi has a normative reference to yang-cbor. Is there
> > a reason that speaks against this?
> 
> Hi,
> 
> The media type could simply say “uses the concept of SIDs” or it could say “uses SIDs as allocated in -sid”.
> I’m not sure the media type needs to say anything at all about this, but if it does, for completeness I think it would need to do the latter (so we can have other media types that get their SIDs elsewhere).
> That would mean a normative reference from yang-cbor to -sid.
> The registry trick turns that around.
>

I want a bit that tells me how instance naming is done, using names or
SIDs. I want to use this to send a query and tell the server that I
want to get CBOR encoded data with SIDS

      GET /restconf/yang-library-version HTTP/1.1
      Host: example.com
      Accept: application/yang-data+cbor;id=sid

or with names are keys

      GET /restconf/yang-library-version HTTP/1.1
      Host: example.com
      Accept: application/yang-data+cbor;id=name

This bit should be defined in YANG-CBOR since this document goes into
quite some detail defining both options to name data.

The question whether alternate schemes can exist to allocate SIDs is
less important for me. I hope multiple schemes to assign SIDs will not
be needed - or only needed in case the scheme defined in the SID
document turns out to be broken up to the point that it can only be
replaced.

That said: A real complication may be the YANG versioning work. Once
publishedd YANG definitions are allowed to change arbitrarily, the
allocation and management of SIDs may get really interesting.

Or is the idea that once we conclude the current SID allocation scheme
to be broken, we go define a SIDplus allocation scheme and then we
still use SIDs in YANG-CBOR but the meaning of the numbers is entirely
different, i.e., we use

      GET /restconf/yang-library-version HTTP/1.1
      Host: example.com
      Accept: application/yang-data+cbor;id=sidplus

to make it clear that the SID numbers now mean something different?
This may make sense and then it may make sense to define

    application/yang-data+cbor;id=name

in YANG-CBOR and to define

    application/yang-data+cbor;id=sid

in the SID document - which means you can't use SIDs with just
YANG-CBOR but only in the context of another document detailing how
SIDs are allocated and managed. Perhaps this is what you have in mind?

Whatever we conclude, it would be nice to get things properly
documented so that we recall the grand plan in N years from now.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
Fax:   [phone]         <https://www.jacobs-university.de/>