Re: [netmod] Meeting Notes from open YANG versioning Design Team meeting

Mahesh Jethanandani <> Fri, 29 March 2019 17:51 UTC

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From: Mahesh Jethanandani <>
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Date: Fri, 29 Mar 2019 10:50:52 -0700
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Subject: Re: [netmod] Meeting Notes from open YANG versioning Design Team meeting
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Hi Robert,

Thanks for putting the minutes together. 

> On Mar 28, 2019, at 1:43 AM, Rob Wilton (rwilton) <> wrote:
> -        These was agreement that IETF models should be limited to a linear revision history, with changes only in the most recent revision.  It was agreed that in some cases it is necessary to make NBC changes (in a new most recent revision) in IETF YANG modules to fix bugs.
> -        There was discussion that an applicability statement could be added, or some of the requirements could be split between SDO vs Vendor requirements, but there did not seem to be strong consensus either for or against this change.  In anything, there seemed to be a slight preference to trying not to make this split.
> -        It was agreed that YANG should have a single versioning scheme that is capable of covering both SDO requirements and vendor requirements.  There was agreement that guidelines text could be used to provide guidance on how IETF models should be versioned.

The combination of these bullet items, and maybe other bullet items does not make clear if there was any consensus in allowing (or maybe even preventing) vendors from using a versioning system to keep track of NBC changes on other (non-latest) branches of the model. I think I heard from multiple vendors (outside of this meeting) that making NBC changes was needed on the non-latest branches, whatever IETF or other SDOs decide. Has that sentiment changed?

If it is the case, the split between the requirements of SDO and the vendors is inevitable.


Mahesh Jethanandani