Subject: [netmod] comments on draft-bjorklund-yang-conformance-problem-00.txt

From: Juergen Schoenwaelder <[email-masked]>
Date: Wed, 18 Feb 2015 10:24:33 +0100

Martin,

thanks for writing up draft-bjorklund-yang-conformance-problem-00.txt.
I think this collection of specific problems we have to solve is very
helpful. A few comments:

- The text above A1 says something about identities but then A1 does
  not talk about identities. I guess it will quite common that leafs
  only support specific subsets of defined identities (and this may
  also be true for certain enums / bits).

- I do not understand the text at the end of 3.2. I also assume that
  foo2 should have the second enum included, no?

- Concerning P3, does 'obsolete' not imply that clients should not
  assume that these nodes will be implemented? So the interesting case
  is mostly 'deprecated', no?

- Concerning P4, I think the server must implement container x if it
  wants to implement and advertise mod-i. If the server cannot
  implement container x anymore, then mod-i can't be implemented. So
  I think P4-01 is the correct solution.

- Concerning P5: Features are module design time partitions, it is
  likely that not all meaningful partitions will always be known at
  design time. P5 is just one special case of this.

  I think the alternative here is to do what SMIv2 did, namely to
  detach compliance definitions from the module definitions so they
  can be managed on their own. Note that SMIv2 rules state that
  conformance groups or compliance statements are never semantically
  changed. The only way to add something to a conformance group or
  compliance statement is to create a new one with a new name.

- Looking at the netmod-2014-12-17-minutes, we had an axiom that said
  that it must be possible to determine which version of a typedef or
  grouping was used to define a leaf. I think this is an important
  thing to keep.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>

---

From: "Jonathan Hansford" <[email-masked]>
Date: Wed, 18 Feb 2015 10:00:47 +0000

In 3.2.2, for consistency shouldn't the enumeration in typedef foo2
also include  enum w?

	In 3.3, s/type if leaf/ype of leafIn 3.3.1 s/modules that
uses/modules that use
One general IETF gripe for those less au fait with the subject matter.
Is there any document anywhere that expands on acronyms? One per WG
would help since they are used not just in documents but even more so
in emails. For example, what is an NP-container? I presume this is to
do with the use of the presence statement but its meaning is not clear
from the context.

----- Original Message -----
From: "Juergen Schoenwaelder" 
To:
Cc:
Sent:Wed, 18 Feb 2015 10:24:33 +0100
Subject:[netmod] comments on
draft-bjorklund-yang-conformance-problem-00.txt

 Martin,

 thanks for writing up
draft-bjorklund-yang-conformance-problem-00.txt.
 I think this collection of specific problems we have to solve is very
 helpful. A few comments:

 /js

 Fax: +49 421 200 3103 

 _______________________________________________
 netmod mailing list
 [email-masked]
 https://www.ietf.org/mailman/listinfo/netmod

---

From: Martin Bjorklund <[email-masked]>
Date: Wed, 18 Feb 2015 15:05:00 +0100 (CET)

Juergen Schoenwaelder <[email-masked]> wrote:
>   only support specific subsets of defined identities

Agreed.  Andy's proposed "get-allowed-identities" is one solution for
this.

> (and this may

In YANG 1.1 you can have if-feature per enum/bit, but unless you have
that, an implemention should implement all enums/bits.

> - I do not understand the text at the end of 3.2.

Which text?

>   I also assume that

Yes, bug.

>   is mostly 'deprecated', no?

Ok.

>   I think P4-01 is the correct solution.

Agreed.

>   compliance statement is to create a new one with a new name.

My worry is that a vendor writes his own compliance statement with the
nodes he chose to implement.  This would essentially let people
implement arbitrary subsets of any standard.

>   grouping was used to define a leaf. I think this is an important

Yes; my intention was that this is covered by axiom A4.

/martin

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From: Juergen Schoenwaelder <[email-masked]>
Date: Wed, 18 Feb 2015 15:23:40 +0100

> > - I do not understand the text at the end of 3.2.

I do not recall anymore, perhaps I got the number wrong or after
re-reading it it is not uncleary anymore. Lets forget it.

> implement arbitrary subsets of any standard.

But then its the vendor's compliance definition and not the standard's
compliance.  A vendor who chooses not to implement the standard will
not implement the standard, I do not think we can do much to change
that.

> Yes; my intention was that this is covered by axiom A4.

Yes, perhaps this is implicitly included in A4. I think a big problem
are changing groupings. If a module uses a grouping in two places and
the grouping gets expanded, then the module is forced to use the
expansion on both places, which may however not be meaningful. With an
expanded type, I can use subtyping. With an expanded grouping, I am
not having any tools to handle this situation.

/js

---

From: Juergen Schoenwaelder <[email-masked]>
Date: Wed, 18 Feb 2015 17:40:53 +0100

Section 3.3.2. refers to P6 which is not in the document, so I guess
the reference is wrong.

/js