Minutes for NETMOD at interim-2015-netmod-15
||Minutes for NETMOD at interim-2015-netmod-15
NETCONF Data Modeling Language WG (netmod)
18th YANG 1.1 Virtual Interim
Monday, August 24th, 2015, 17:00-18:00 CEST
Minutes Juergen Schoenwaelder
AB = Andy Bierman
IB = Ignas Bagdonas
JS = Juergen Schoenwaelder
LL = Ladislav Lhotka
MB = Martin Bjorklund
* Review of Goals and Milestones
The WG charter lists the following milestones:
Mar 2015 - Submit YANG 1.1 to the IESG
Apr 2015 - Submit YANG guidelines update to the IESG
Is the goal to wrap up YANG 1.1 with the feature set we agreed on
during the last year or is the goal to keep YANG 1.1 a moving target
for some additional time so that additional features can be
incorporated? This may also touch on the question what can be done
with extensions. Whatever the answer is, we should agree on a plan
how to move forward with the YANG 1.1 effort and then set realistic
LL: If we do not finish YANG 1.1 quickly, we have to remove the
dependency on YANG 1.1 from other documents.
AB: If we want to address I2RS or OpenConfig requirements, it might
take anything between a months or a year.
MB: Can we not make extensions work in YANG 1.1?
LL: We need negotiation of extensions and attributes.
MB: But this is a different problem.
MB: You can design extensions such that they do not badly affect
clients. The NACM extensions work just fine.
AB: I prefer to update the language instead of having a core
language and N extensions of it.
MB: I prefer to have modularity. Eventually certain extensions may
become part of the language but revising the language every time
a new extension is needed is costly.
LL: Should annotations be part of YANG 1.1?
MB: Annotations define meta-data not regular data nodes.
MB: I think we should focus on YANG 1.1 but I do not like to find
myself in a situation that we have to add many additional
statements once YANG 1.1 is done.
MB: We had extensions like actions that worked fine because a client
not understanding an action would never invoke one. But yes, you
can define extensions that can break things.
LL: I think the YANG language should address the extension
AB: There is conformance to YANG, but also conformance to NACM or
conformance to EPHEMERAL.
LL: What if I implement ietf-system but not NACM? Do I still have to
implement nacm: extension semantics?
LL: I am concerned about vendors misusing extensions.
MB: Vendors can always break things.
MB: I think we should finish YANG 1.1 soon as we have it now.
MB: If we have to do YANG 1.2 afterwards, so be it. It would also be
nice to avoid this if we can work with extensions.
AB: I do not mind revising YANG every lets say two years if needed.
MB: I think we agree that we should finish YANG 1.1 now.
JS: What is a realistic timeline to finish up YANG 1.1?
AB: What about delivering YANG 1.1 in October?
MB: Works for me.
AB: Ideally, the next Internet-Draft should go to WG last call.
MB: Lets discuss next week whether we do another I-D or not.
- MB will go though the various comments sent to the WG list and
identify comments that are easy to address and comments that
- JS will change YANG 1.1 milestone to October 2015
- JS will change the YANG guidelines milestone to December 2015