Le mardi 04 mars 2008, Evangelos Chaniotakis a écrit :
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.
I tortured myself to find the good word to represent what i mean. First i used the term of "View" but view implies that a description is already here. The model concept is not only a view, it is a network modelisation itself which can be connected with others model.
But otherwise, thanks for writing this up. This is really close to work currently under development in the IDC project.
regards, -- Aurélien Cedeyn Comité Technique Grid'5000 Lyon Bureau 364 Nord Tel: +33 4 72 72 82 30 Laboratoire de l'Informatique du Parallélisme (LIP) Ecole Normale Supérieure de Lyon 46 Allée d'Italie 69364 Lyon Cedex 07 - France