Rob, FWIW, an updated version with changes to address your review is available online:
URL: https://www.ietf.org/id/draft-ietf-opsawg-model-automation-framework-05.txt Status: https://datatracker.ietf.org/doc/draft-ietf-opsawg-model-automation-framework/ Htmlized: https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-model-automation-framework Htmlized: https://tools.ietf.org/html/draft-ietf-opsawg-model-automation-framework-05 Diff: https://www.ietf.org/rfcdiff?url2=draft-ietf-opsawg-model-automation-framework-05 Please let us know if any of your comments is still pending. Thank you. Cheers, Med > -----Message d'origine----- > De : mohamed.boucad...@orange.com > [mailto:mohamed.boucad...@orange.com] > Envoyé : lundi 7 septembre 2020 16:35 > À : Rob Wilton (rwilton) <rwil...@cisco.com>; opsawg <opsawg@ietf.org> > Cc : draft-ietf-opsawg-model-automation-framework....@ietf.org > Objet : RE: AD review for draft-ietf-opsawg-model-automation- > framework-04 > > Hi Rob, > > Thank you for the detailed review. > > Please see inline. > > I let my co-authors further comment. > > Cheers, > Med > > > -----Message d'origine----- > > De : Rob Wilton (rwilton) [mailto:rwil...@cisco.com] Envoyé : > vendredi > > 4 septembre 2020 19:22 À : opsawg <opsawg@ietf.org>; > > draft-ietf-opsawg-model-automation- > > framework....@ietf.org > > Objet : AD review for draft-ietf-opsawg-model-automation-framework- > 04 > > > > Apologies for the lengthy delay in performing the AD review. > > > > I found that this document to be well written so I would like to > thank > > the authors, WG, and doc shepherd for that. My more significant > > comments relate to questions on the scope of this architecture. > > > > > > More significant comments: > > > > 1. By "Data Model" does this document mean "YANG data model"? And > if > > so, does it take this meaning all through this document, or only > some > > of the time? > > > > [Med] "Data Model" is used as a generic term as per rfc3444#section-4. > We are using "YANG data models" or "YANG module" when we wanted to be > more specific about the DM flavour. > > I double checked the text to make sure this is consistently used along > the document. Updated some occurrences in the text where the use of > "YANG data model" is more accurate. > > > 2. Generically, service data models are not necessarily written in > > YANG (e.g., I think that MEF are defining them using OpenAPI). So, > > related to (1), is this architecture intended to be tied to only > > service models defined in YANG, or be more broadly applicable? > > [Med] We don't require the service models to be YANG-modelled (see for > instance the example depicted in Figure 2). That's said, the use of > YANG in all levels would ease mapping operations. > > > > > 3. This architecture seems to quite strictly represent 3 layers > > (service, network, device). Does it envisage that these layers may > > themselves be deconstructed? E.g. a customer service can be > > constructed from underlying services > > [Med] Yes, that's not excluded. The architecture can be "recursive" > (Such as rfc8597#section-3.1.3). > > (e.g., as discussed in section > > 3.1, but more as an East-West relationship). Similarly, device > models > > could also be deconstructed, e.g., if the dataplane is decoupled > from > > the control plane, or if a device itself acts as a controller > managing > > other devices. > > [Med] The document does not make assumptions on the organic structure > or where the functions are provided. Having a controller co-located > with other YANG-controlled functions is not excluded. > > > > > 4. My minimal understanding of the MEF LSO architecture was that > they > > put quite a lot of emphasis on East-West models, probably at the > > service layer. Is this effectively the same as what is described in > > Figure 1 in section 3.1? > > [Med] Inter-domain interactions between two services or two adjacent > networks are not shown in Figure 1. This figure focuses mainly on the > interface between a service and an underlying network. > > Does the potential existence of these East- > > West APIs need to be described in any more detail? > > > > [Med] A network can act as a "customer" and request services from > other networks. The peer network will then follow the levels depicted > in the architecture. This is for example hinted in this text for > example: > > o allow customers (or Network Operators) to dynamically adjust the > network resources based on service requirements as described in > Service Models (e.g., Figure 2) and the current network > performance information described in the telemetry modules. > > We can add some more text if needed. > > Section 4.3 discusses how multi-domain mapping can be handled at the > server level. This assumes that the interaction is not between the > domains themselves but driven by the service layer. > > > > > Minor comments/clarifications: > > > > Section 3.1: Data Models: Layering and Representation > > > > 5. Network Models are mainly network resource-facing modules; they > > describe various aspects of a network infrastructure, including > > devices and their subsystems, and relevant protocols operating at > > the > > link and network layers across multiple devices (e.g., network > > topology and traffic-engineering tunnel modules). > > > > Would it be fair to say that Network Models might be protocol > > specific, or might be generalized? If so, is that worth mentioning? > > > > [Med] Network models may include some protocol-specific parameters. > I'm neutral whether this needs to be mentioned in the text. > > > > > 6. Re: DOTS & RFC 8783, I'm not sure how well the YANG model defined > > in that drafts fits into the category of Service YANG model. > > > > [Med] RFC8783 defines the filtering service requested by a > client/customers; how this request triggers the selection of the > devices that need to be configured, the exact set of ACLs, and the > enforcing of the ACLs in these devices is managed by other layers > (RFC8519). From that perspective, we do think that the module in RFC > 8783 satisfies the following from RFC8309: > > "Details > included in the service model include a description of the service > as > experienced by the customer, but not features of how that service > is > delivered or realized by the service provider. " > > > 7. Pipe vs hose vs funnel. Are these terms, or do they need to be, > > defined somewhere? In particular it is not obvious to me what the > > distinction is between pipe vs hose. > > [Med] "pipe" means that only point-to-point communications are allowed > while "hose" means that communications from one to N is allowed. > > We can text to explain this. > > > > > > > In Appendix A: > > 8. Would it be useful to discuss or reference YANG Catalog (as a > > source of querying YANG models), the public YANG github repository, > or > > YANG module tags as a method of organizing YANG models? > > > > [Med] Good point. Will consider adding some text. > > > 9. > > o Tunnel identities to ease manipulating extensions to specific > > tunnels [RFC8675]. > > > > I found this sentence slightly unclear. Perhaps it could be > reworded? > > > > [Med] Fair point. Updated to : > > " o Tunnel identities: [RFC8675] defines a collection of YANG > identities used > as interface types for tunnel interfaces." > > > 10. > > o Generic Policy Model: > > > > The Simplified Use of Policy Abstractions (SUPA) policy-based ... > > > > It does not like this draft is going anywhere, and I'm not convinced > > that it is really helpful to reference it here. Or, if it must be > > referenced, it should be caveated accordingly. > > > > [Med] Fair enough. I tend to agree with you. > > > 11. > > A.3. Device Models: Samples > > > > I think that it would be helpful if this diagram, and the list in > > section A3.2, had references to the interface YANG module. > > > > [Med] Point taken. > > > 12. > > A.3.1. Model Composition > > > > o Device Model > > > > [I-D.ietf-rtgwg-device-model] presents ... > > > > Again, I'm not sure that this is a helpful reference, given that the > > approach defined in this draft did not gain traction, and instead, a > > more loosely coupled structure was preferred. E.g., I see that tags > > (and arguably schema mount) solve this organizational problem in a > > more flexible way. > > > > [Med] Fair point. > > > 13. > > A.3.1.1. Schema Mount > > > > That capability does not cover design time. > > > > This sentence is unclear on its own. Perhaps either expand it or > > remove it > > [Med] OK. _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. 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