Juergen Schoenwaelder <[email protected]> wrote: > I do not think the goal should be to emulate SMIv2 compliance levels > using features. So I propose to do nothing about entity4CRCompliance.
Ok. > The other question (which should perhaps have been a separate issue) > is whether non-existing values are indicated by zero-length strings or > non-existing objects. I think in general we prefer to simply not > report those objects in the YANG world. I agree. > If so, I am not sure whether > the goal to not depart too much from the ENTITY-MIB overrules > this. Note that there are a couple of objects where non-existing > values lead to zero-length string or other special values. I think this "depature" is fine. > (The > 'alias' description is kind of interesting - the server may set the > value of this node to a locally unique value; entPhysicalAlias says > something different, namely On the first instantiation ... is set to > the zero-length string.) The MIB says that the object is set to a zero-length string OR a locally unique value. After this a manager can change this value. So I believe this semantics is reflected in the YANG model (esp. if we make it clear that a zero-length string in the MIB maps to a non-existing node in YANG). > Looking at the YANG fragment, I am also not sure how useful it is to > carry the 32 'something' restriction forward. Note that 32 means > unicode characters in YANG but space of the UTF-8 encoding of > characters for SMIv2 (since it all ends up being a restriction for the > OCTET STRING). Perhaps this deserves a feature, namely, whether an > implementation supports flexible names or restricts names according to > the SMIv2 ENTITY-MIB rules. Hmm, this cannot easily be done with a YANG feature, but maybe we can simply change these strings to unrestricted strings, and then state that a server MAY impose additional restrictions on valid values? /martin > /js > > On Thu, Dec 15, 2016 at 04:01:10PM +0100, Martin Bjorklund wrote: > > Hi, > > > > Issue https://github.com/netmod-wg/entity/issues/11 > > > > RFC 6933 introduced a new compliance level for constrained resources > > - entity4CRCompliance. Do we need a corresponding feature? > > > > In YANG, we cannot to the equivalent of compliance levels, so we would > > need to mark all nodes with some optional feature, except the few > > nodes that a constrained device would implement. > > > > OTOH, most nodes are already optional and config false. So a > > constrained server that doesn't know the serial number for example > > could just no return it. There is one catch though; the current text, > > copied from the MIB, says e.g.: > > > > If the manufacturer name string associated with the > > physical component is unknown to the server, then this > > node will contain a zero-length string. > > > > Maybe we should change this so that the object isn't returned at all > > instead of returning a zero-length string. > > > > > > > > /martin > > > > _______________________________________________ > > netmod mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/netmod > > -- > 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 [email protected] https://www.ietf.org/mailman/listinfo/netmod
