Subject: [Teas] Fwd: [Rtg-yang-coord] Fwd: Important: Guidelines for YANG module authors

From: Lou Berger <[email-masked]>
Date: Fri, 9 Jun 2017 10:48:06 -0400

FYI -

Now that this guidance is out, we (as a WG) should be able to progress
yang models as we see fit.  Understanding and agreeing to the impact to
the TE Topology model is probably highest priority (for the WG's YANG docs.)

Lou

-------- Forwarded Message --------
Subject: 	[Rtg-yang-coord] Fwd: Important: Guidelines for YANG module
authors
Date: 	Fri, 9 Jun 2017 16:00:45 +0200
From: 	Benoit Claise <[email-masked]>
To: 	Routing WG <[email-masked]>, [email-masked]
<[email-masked]>

Dear all,

FYI.
If this topic requires some discussion, let's use the netmod mailing list.

Regards, Benoit

-------- Forwarded Message --------
Subject: 	Important: Guidelines for YANG module authors
Date: 	Fri, 9 Jun 2017 15:56:39 +0200
From: 	Benoit Claise <[email-masked]>
To: 	NETMOD Working Group <[email-masked]>

Dear all,

Now that the new NETMOD and NETCONF charters have been approved, it's
time to think about the guidelines for YANG module authors.

The Network Management Datastore Architecture (NMDA) addresses the
so-called "OpState problem" that has been the subject of much discussion
in the IETF. NMDA is still in development, and there will be a
transition period before NMDA solutions are universally available.

The NETMOD Datastore Design Team and the Routing Yang Architecture
Design Team have worked with Alia and Benoit to create initial
guidelines for how the NMDA, as defined in
draft-ietf-netmod-revised-datastores
<https://datatracker.ietf.org/doc/draft-ietf-netmod-revised-datastores/>,
impacts Yang models. The draft-dsdt-nmda-guidelines
<https://datatracker.ietf.org/doc/draft-dsdt-nmda-guidelines/>
individual draft was foundational in helping creating those guidelines.

If you have questions or concerns on how these guidelines should apply
to work of interest, please contact your WG Chairs or ADs.

It is our strong recommendation, as ADs with agreement from the NETMOD
WG Chairs, that models SHOULD move as quickly as possible to the NMDA.
The specific approach to be taken for models being developed now and
during the NMDA transition period should be based on both the expected
usage and the maturity of the data model.

1. New models and models that are not concerned with the operational
state of configuration information SHOULD immediately be structured to
be NMDA-compatible.

2. Models that require immediate support for "in use" and "system
created" information SHOULD be structured for NMDA. Then derived
versions of these models SHOULD be created, either by hand or with
suitable tools, that follow the current modeling strategies. In some
cases, the non-NMDA model may be an existing model and not derived from
the NMDA model. In all cases, the NMDA and non-NMDA modules SHOULD be
published in the same document, with NMDA modules in the document main
body and the non-NMDA modules in an Appendix. The use of the non-NMDA
model will allow temporary bridging of the time period until NMDA
implementations are available. The non-NMDA module names should include
’-state’ appended.

We would like to thank Kent Watsen, Lou Berger, Rob Wilton, Martin
Bjorklund, Phil Shafer, Acee Lindem, Chris Hopps, Juergen Schoenwaelder,
and all others who helped develop these guidelines.

Regards,
Alia Atlas, Routing AD
Deborah Brungard, Routing AD
Alvaro Retana, Routing AD
Warren Kumari, Operations & Management AD
Benoit Claise, Operations & Management AD