[CCAMP] A YANG model to link Termination Point to Interface was :Re: Breaking out generic models from draft-ietf-ccamp-mw-topo-yang

[tom petch <[e-mail]>]

The augmentation is to 
"/nw:networks/nw:network/nw:node/nt:termination-point/tet:te" 
Why?  Why not 
"/nw:networks/nw:network/nw:node/nt:termination-point/"
I do not see the te connection; to me it looks useful to any model with a termination point and not related to te..  If there is a case for /te/ then I would think that the model belongs in TEAS.  If not, well I2RS is no more so perhaps OPSAWG where it could get a wider review.

Second, I wonder about the relationship of TP and IF.  Modelling networks used to be simple, nodes and edges.  Then, 1980s, the ends of the edges got separated from the node which I probably understand.  Recently there was an I-D on SAP, not the OSI SAP, not the mobile phone SAP; the I-D was clear that a SAP was not a link nor a tunnel termination point but less clear, to me, what it was.   I struggled to see what structure it was proposing, as, judging from the reviews, did many reviewers. It did map the SAP in YANG to an interface type and catered for sub-interfaces and attachment interfaces.

I note that here the leaf in the model is named ...interface-path which seems odd to me.

What I am fishing for here is what is the structure of a node nowadays.  It is the sort of thing that the ITU-T is good at, the IETF less so, and while mapping a termination point to an interface seems reasonable, I am conscious that such modelling, in other spheres, turns out to be problematic at a later date because the underlying concepts are not quite right, mixing apples and oranges

Tom Petch.

________________________________________
From: CCAMP <[e-mail]> on behalf of tom petch <[e-mail]>
Sent: 24 November 2022 17:12
Subject: Re: [CCAMP] Breaking out generic models from draft-ietf-ccamp-mw-topo-yang

From: CCAMP <[e-mail]> on behalf of Jonas Ahlberg <jonas.ahlberg=[e-mail]>
Sent: 23 November 2022 07:49

Hi all,

In the current version of draft-ietf-ccamp-mw-topo-yang there are a total of three models.
https://datatracker.ietf.org/doc/draft-ietf-ccamp-mw-topo-yang/

  *   ietf-microwave-topology.yang

A model which augments te-topology with microwave specific extensions

  *   ietf-bandwidth-availability-topology.yang

This is a module for defining a bandwidth availability matrix,

for links in a topology. It is intended to be used in conjunction
with an instance of ietf-network-topology and its augmentations

  *   ietf-tp-interface-reference-topology.yang

This is a module for defining a reference from a termination
point in a te-topology to a list element in interfaces as defined in RFC 8343

The last two are generic and can not only be used for a microwave topology but for any transport technology/topology. Therefore we plan to break out those two models from the microwave specific draft and instead put them in a new draft which in a better way reflects that they are generic.

<tp>
Bad idea:-(  A three way split is a no-brainer to me.

The network model has been augmented recently with 'node' gaining useful information such as node type, MAC usage, IPv4 routes, IPv6 routes and so on.  This you would be unlikely to divine from the title of the I-D (which contains the augmentation) or indeed from reading the I-D; which I did and it passed me by.  Only by reverse engineering the YANG might you see these possibly useful, generic additions for network models (unless, that is, you are the author).  Were these additions in an I-D with a relevant title then perhaps the wheel will not be reinvented at some later date.

So, three I-D with relevant titles.  Yes, two are small and it would be nice for there to be more substance to them but more could get added in a revision.

Which WG is suitable for the two new ones?  TEAS? OPSAWG?  Tucked away in CCAMP they might not be noticed.

Tom Petch.

We would like to get your feedback on this proposed change.

Regards
Jonas Ahlberg
on behalf of the microwave team

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