Re: [Rtg-yang-coord] naive question ??

> On Feb 6, 2015:12:07 AM, at 12:07 AM, Loa Andersson <loa@pi.nu> wrote:
> 
> Tom,
> 
> On 2015-02-05 20:27, Thomas D. Nadeau wrote:
>> 
>>> On Feb 5, 2015:5:51 AM, at 5:51 AM, Loa Andersson <loa@pi.nu> wrote:
>>> 
>>> Folks,
>>> 
>>> I have what might be a naive question.
>>> 
>>> People have told me that in Yang we want to separate functionality from
>>> technology, i.e. we will look at OAM, management, routing, signaling
>>> and traffic engineering as aggregate functions and build our tree based
>>> on that.
>>> 
>>> Now if we are to model thing that are closely related e.g. MPLS OAM,
>>> signaling, routing and traffic engineering, does that mean that we have
>>> to work at separate pieces of the yang tree and repeat this for every
>>> piece of the technology?
>> 
>> 	I think you can do a model dedicated to MPLS OAM.  The analogy is
>> pretty much similar to how MIBs are created. You can import bits or
>> objects from all over the place to create things, or you can recreate them
>> in place.   There is a trade-off about modularity versus time-to-completion
>> here and I very much am not in favor of being zealous one way or the other.
>> 
>> 	We also need to very much take an iterative process around these models:
>> they are not set in stone, and we should iterate on them to modify, adapt
>> and update them as necessary.  With that in mind, we've been encouraging people to
>> just starting writing them as best as possible and implementing either prototype
>> code or actually putting them into products so that we can see how they actually
>> operate in the wild.
> 
> I thought there were activities going on to define an overall IETF yang
> model, right? If we say we approach this in an iterative way would the
> overall yang-model be the outcome of that process, rather than an input
> to it. Or do I miss something?

	There is no such thing as an overall model; we have models that fit
together.  The hope is that the output is a model, but assuming it will never
evolve is very much an old way of thinking about how modern software engineering
works. Artifacts are ephemeral and adapt/evolve or are sidelined quickly. 

	--Tom


> 
> /Loa
>> 
>> 	--Tom
>> 
>> 
>>> First, is this correctly understood or do I have to go back and discuss
>>> this again with the people proposing it?
>>> 
>>> If it is correct why is it superior to what we did for SNMP, one MIB-module for each protocol?
>>> 
>>> Are the decisions taken or is the jury still out?
>>> 
>>> /Loa
>>> --
>>> 
>>> 
>>> Loa Andersson                        email: loa@mail01.huawei.com
>>> Senior MPLS Expert                          loa@pi.nu
>>> Huawei Technologies (consultant)     phone: +46 739 81 21 64
>>> 
>>> _______________________________________________
>>> Rtg-yang-coord mailing list
>>> Rtg-yang-coord@ietf.org
>>> https://www.ietf.org/mailman/listinfo/rtg-yang-coord
>>> 
>> 
> 
> -- 
> 
> 
> Loa Andersson                        email: loa@mail01.huawei.com
> Senior MPLS Expert                          loa@pi.nu
> Huawei Technologies (consultant)     phone: +46 739 81 21 64
>