Re: [Teas] WG Adoption Poll - draft-king-teas-applicability-actn-slicing-10

[Daniele Ceccarelli <[e-mail]>]

Hi Adrian,

We’re getting there.
Let’s try in line this time.
Cheers,
Daniele


From: Adrian Farrel <[e-mail]>
Sent: den 2 september 2021 14:37
To: Daniele Ceccarelli <[e-mail]>
Cc: 'TEAS WG' <[e-mail]>
Subject: RE: [Teas] WG Adoption Poll - draft-king-teas-applicability-actn-slicing-10

Hi, yet again,

I’d be surprised if draft-ietf-teas-actn-yang suggested the use of the NBI at the moment because the NBI is still an individual draft – we don’t even know whether the working group wants to adopt it yet. draft-ietf-teas-actn-yang  cannot hope to list all possible future customer service models. But maybe a future version will include the NBI in the list in Section 4.1 when the NBI is stable.
[DC] I said it is suggesting to use the existing models like service network models (LxNM), TE models (TE topo, TE tunnel, VN) and the TE service mapping etc, not the network slicing one.

I don’t think that Figure 1 of draft-king-teas-applicability-actn-slicing-10 says that the NSC NBI can be replaced with the CMI. Rather, it says that the NSC NBI can be used to instantiate the CMI. That is, the CMI is an abstract interface in the architectural model, and a number of YANG models can be used to instantiate the CMI depending on the function being offered. That is, I think, exactly what Section 4.1 of draft-ietf-teas-actn-yang says.
[DC] I don’t disagree with you here. In the context of ACNT the term CMI means a set of models, in the context of network slicing another (the NS NBI), in none of them it could just be a subset (e.g. L3NM). I would have preferred that the NS NBI would have augmented them instead of defining something orthogonal.

Which model(s) an operator chooses to use at the CMI depends does not depend on whether they support ACTN or not. If they don’t support ACTN, they don’t have a CMI, end of story. But if they *do* use the ACTN architecture, they may offer one or more services to their customer. For each service they offer, they (may) use a different customer service model.

If the provider wants to use slicing based on the VN model or the L3SM then that’s OK, and they don’t need to use the NSC NBI. On the other hand, they can offer ”slicing as a service” and may choose to use the NSC NBI for this.
[DC] Agree. Can we call the draft: “A service model for IETF network slice NBI” ? And in the text say that the model is one of the options that can be used as a “network model” ?

Cheers,
Adrian

From: Daniele Ceccarelli <[e-mail]<mailto:[e-mail]>>
Sent: 02 September 2021 12:54
To: [e-mail]<mailto:[e-mail]>; 'Vishnu Pavan Beeram' <[e-mail]<mailto:[e-mail]>>; 'TEAS WG' <[e-mail]<mailto:[e-mail]>>
Cc: 'TEAS WG Chairs' <[e-mail]<mailto:[e-mail]>>
Subject: RE: [Teas] WG Adoption Poll - draft-king-teas-applicability-actn-slicing-10

Hi Adrian,

Good point, you’re right...not accurate from my side.

Since ACTN, in addition to being a framework, is also suggesting which models to use, when I speak about ACTN I’m implying also the usage of those models: i.e. service network models (LxNM), TE models (TE topo, TE tunnel, VN) and the TE service mapping etc.

I’m referring to draft-ietf-teas-actn-yang-07<https://datatracker.ietf.org/doc/html/draft-ietf-teas-actn-yang-07> section 4.1 for the CMI and 4.2 for the MPI.



I don’t have anything against the usage of this model as service model, but I see competition with the existing ones as a network model.

I think Kenichi explained it extremely well in his mail:



“1) According to Figure 1 of draft-king-teas-applicability-actn-slicing-10, NSC NBI can be replaced with CMI. If the new nbi is created, we have to parallelly implement two nbis or just wrap CMI with NSC NBI. From one of mobile operators' capex perspective, we don't want to do such effort, since we believe major ietf network slice requirements can be covered by ACTN.”



BR
Daniele







From: Adrian Farrel <[e-mail]<mailto:[e-mail]>>
Sent: den 2 september 2021 11:54
To: Daniele Ceccarelli <[e-mail]<mailto:[e-mail]>>; 'Vishnu Pavan Beeram' <[e-mail]<mailto:[e-mail]>>; 'TEAS WG' <[e-mail]<mailto:[e-mail]>>
Cc: 'TEAS WG Chairs' <[e-mail]<mailto:[e-mail]>>
Subject: RE: [Teas] WG Adoption Poll - draft-king-teas-applicability-actn-slicing-10

Hi again Daniele,

> That’s a quibble that only solves the issue partially.
> Should we use ACTN to do network slicing in networks that support
> ACTN and the Network Slicing NBI model in networks that’s don’t
> support it?

You are comparing two things that are not the same.
The Network Slicing NBI is a YANG model for use on the customer service interface. That is, it allows the customer and provider to communicate about the network slice that is to be provided.
ACTN is an architecture. That is, it describes how the management components may be arranged/structured to deliver function in a network.

You can use the Network Slicing NBI at an interface in the ACTN architecture.
It could be used at the CMI (in the same way that the L3SM and L2SM can be): see Section 4.1.
Or it could be used above the CNC: see Section 4.2

Best,
Adrian