[Nml-wg] About modelisation of the network description

[Evangelos Chaniotakis]

Aurélien Cedeyn wrote:
> Le samedi 01 mars 2008, Freek Dijkstra a écrit :
>   
>> Aurélien Cedeyn wrote:
>>     
>>> I send you a little document that i made which describes a new object in
>>> the NML : the model object. All the description and motivation about this
>>> addon are in the attached document.
>>>       
>> Aurélien, thank you so much! Very good write down! These are the
>> contributions that will help the NML workgroup a lot.
>>
>>     
>
> Hi Freek,
> What an impressive mail :)
> I'll try to answer shortly but clearly to your questions.
>
>   
>> I wholeheartedly agree with what you write, although I use different
>> terms, and I don't understand all details of what your propose yet.
>> Allow me to ask a bit, so I'll understand.
>>
>>     
>>> The NML goal is to instance modelisations of the real topology. This
>>> real topology is too complex regarding the description needs of
>>> applications, some informations are not needed.
>>>       
>> True, and true. But I think that modelling of the real topology is only
>> ONE OF the goals of NML. What you write is that you also like to see NML
>> capable of describing "modelisations" of the real topology (I would call
>> it abstractions of the real topology). I wholeheartedly agree that that
>> should also be another goal of NML.
>>
>> First a rather academic remark: what exactly is a "real topology" and a
>> "modelisation" or "abstracted" topology? Most network engineers, even
>> when asked for the "real topology" will describe fibers and devices, but
>> still abstract a lot: they often leave out patch panels, and the
>> internal workings of devices itself: because they either find it
>> irrelevant (decribing patch panels is only relevant if you care about
>> inventory management, or power loss details) or because they simply
>> don't know the information (few people know how exactly devices work on
>> the component level). In short: nearly everything is already a
>> "modelisation", although the level of abstraction greatly differs
>> between each model, and it is there where the discussion starts.
>>
>>     
>
> Exactly, that's what i mean with "Modelisations". The question is : "Does NML 
> have to provide the extrem details of a real network such as patch panel ?"
>   

Can we call them "Views" instead of "Models"? "Model" is a quite overloaded
word, especially in a semantic context.

But otherwise, thanks for writing this up. This is really close to work 
currently
under development in the IDC project.