Re: [Netconf] [Gen-art] Genart last call review of draft-ietf-netconf-nmda-netconf-06

[Martin Bjorklund <[e-mail]>]

Juergen Schoenwaelder <[e-mail]> wrote:
> On Tue, Jul 31, 2018 at 02:27:36PM +0000, Christer Holmberg wrote:
> > 
> > >> Related to that, it would also be good to have an interoperability
> > >> statement, saying that implementations that implement the draft will
> > >> still work with implementations that do not.
> > >
> > > This primarily concerns clients: They need to be able to fallback to
> > > using <edit-config> instead of <edit-data> and <get> instead of
> > > <get-data> if they communicate with a non NMDA NETCONF server. I am
> > > not sure whether this is a "SHOULD be able to fallback" or a "MUST be
> > > able to fallback".
> > 
> > If you use MUST, you guarantee that fallback will always work (assuming implementations follow the spec). If you use SHOULD, I think you'll need some additional discussion on when it doesn't apply, what to do then, etc.
> > 
> > So, my suggestion (from a reviewer perspective) would be MUST.
> >
> 
> I am not sure about this. It is very well possible that in a few years
> client implementations may require NMDA and instead of trying a
> fallback they stop if the peer does not support NMDA. The complexity
> of clients varies widely, ranging from implementations that can hide
> the complexities behind an API to simple scripts without much fallback
> complexity. If we write MUST, it will be ignored in practice by a
> certain fraction of clients.

I agree.  I don't even think we should write SHOULD.  IMO we shouldn't
make such requirements on the clients at all.


/martin