On Tue, Jun 13, 2017 at 11:52 AM, Ladislav Lhotka <lho...@nic.cz> wrote:
> Andy Bierman <a...@yumaworks.com> writes: > > > On Mon, Jun 12, 2017 at 10:21 AM, Juergen Schoenwaelder < > > j.schoenwael...@jacobs-university.de> wrote: > > > >> On Fri, Jun 09, 2017 at 10:55:20AM +0000, Bogaert, Bart (Nokia - > >> BE/Antwerp) wrote: > >> > > >> > We have a question regarding the statistics container as defined in > the > >> > interfaces-state model. This container defines one mandatory leaf > >> > (discontinuity-time) while all other leafs are optional. What is the > >> > rationale behind this leaf being mandatory and not an optional field? > >> > > >> > It does not make a lot of sense to return a discontinuity-time value > and > >> no > >> > counters if none of the counters are relevant for a specific > interface. > >> > > >> > Another alternative could be to add, via a deviation, a when clause to > >> the > >> > container indicating for which ifType(s) the container is (or is not) > >> > present. But that would lead to not supporting the IETF interfaces > model > >> to > >> > the full extent. > >> > > >> > >> The discontinuity-time is relevant for _any_ counter associated with > >> an interface, regardless whether the counter is defined in the > >> interfaces model or elsewhere. I have a hard time to imagine an > >> interface that has zero counters. > >> > >> > > The mandatory-stmt is very confusing for config=false nodes. > Mandatory=true > > means > > an <rpc-reply> must contain an instance of the mandatory leaf. > > I don't think it is that confusing. RFC 7950 defines what a valid data > tree means and "mandatory" are among the constraints. > > I agree though that in terms of a management protocol it means different > things for config true and false data, but this is true also for default > values and maybe other YANG concepts as well. > > > > > Mandatory=false does not mean optional-to-implement although it sure > > looks that way for config=false nodes. Only if-feature can make a node > > optional to implement. > > I don't think this interpretation is supported by any text in the YANG > spec. State data nodes that are optional needn't be implemented. > > RFC 7950, sec 5.6 (Conformance) does not support your interpretation. It defines basic behavior, optional (via features), and deviations as the only mechanisms affecting conformance. Lada > > > > Andy > > > > > > /js > > > > > > Andy > > > > -- > >> 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/> > >> > >> _______________________________________________ > >> netmod mailing list > >> netmod@ietf.org > >> https://www.ietf.org/mailman/listinfo/netmod > >> > > _______________________________________________ > > netmod mailing list > > netmod@ietf.org > > https://www.ietf.org/mailman/listinfo/netmod > > -- > Ladislav Lhotka, CZ.NIC Labs > PGP Key ID: 0xB8F92B08A9F76C67 >
_______________________________________________ netmod mailing list netmod@ietf.org https://www.ietf.org/mailman/listinfo/netmod
