Re: [Actn] ACTN progress

[윤빈영 <[e-mail]>]

Hi Young,

I have a question about the sentence that the MDSC acts as a conduit to the PNC when the CNC talks to the PNC “transparently”.
Rather than the conduit as a role of the MDSC, I think that the MDSC still need to provide for adaptation function like the customer VN mapping function.
It is because the PNC doesn’t support the customer VN mapping function to support the VN services of the CNC in ACTN.

Sincerely yours,

From: Leeyoung [mailto:[e-mail]]
Sent: Tuesday, January 20, 2015 6:28 AM
Subject: Re: [Actn] ACTN progress

Hi Arashmid,

Yes. That is how I see.

Thanks,
Young

From: Arashmid Akhavain
Sent: Monday, January 19, 2015 3:23 PM
To: Leeyoung; Igor Bryskin; Daniele Ceccarelli; 윤빈영; [e-mail]<mailto:[e-mail]>
Subject: RE: [Actn] ACTN progress

Thanks for your comment Young.
Yes, the MDSC would be still present in the architecture, but it simply acts as a conduit to PNC. The CNC as Igor and you mentioned is not aware of the underlying hierarchy.

Arashmid

From: Leeyoung
Sent: 19 January 2015 16:08
To: Igor Bryskin; Arashmid Akhavain; Daniele Ceccarelli; 윤빈영; [e-mail]<mailto:[e-mail]>
Subject: RE: [Actn] ACTN progress

Hi Arashmid and Igor,

I think you guys are talking about the same thing. From an interface standpoint, the CNC would have an interface to a network controller. It can be a MDSC or a PNC or a combo, but the CNC would not care what type of controller it interfaces with.

When the CNC interfaces with the PNC type of controller in the network, then in effect MDSC function can be said “bypassed”, but, from an interface standpoint, we should make the design “transparently” irrespective of CNC-MDSC or CNC-PNC or CNC-MDSC-PNCs.

Thanks,
Young

From: Igor Bryskin [mailto:[e-mail]]
Sent: Monday, January 19, 2015 2:15 PM
To: Arashmid Akhavain; Daniele Ceccarelli; 윤빈영; Leeyoung; [e-mail]<mailto:[e-mail]>
Subject: RE: [Actn] ACTN progress


Hi Arashmid

When CNC talks down, it does not know (nor makes assumptions) whether it talks to MDSC or PNC. In either case it uses the same API.

Igor

From: Arashmid Akhavain [mailto:[e-mail]]
Sent: Monday, January 19, 2015 2:02 PM
To: Daniele Ceccarelli; 윤빈영; Leeyoung; Igor Bryskin; [e-mail]<mailto:[e-mail]>
Subject: RE: [Actn] ACTN progress


Hi Daniele,  all,



I agree that the MDSC and PNC functionalities can be provided by a single controller. I also agree that a single controller can be both MDSC and PNC.

But does this mean that we bypass the MDSC functional block in these cases? Or a request from CNC still goes through MDSC block and then to PNC block?



Bsst Regards,

Arashmid

From: ACTN [mailto:[e-mail]] On Behalf Of Daniele Ceccarelli
Sent: 18 January 2015 04:46
To: Arashmid Akhavain; 윤빈영; Leeyoung; Igor Bryskin; [e-mail]<mailto:[e-mail]>
Subject: Re: [Actn] ACTN progress

Hi Arashmid, all,

Up to now we have always considered the 3-level model but it is possible to say that is also include the 2-level model. From an implementation point of view we can have a CNC interfacing with a single controller which implements MDSC and PNC functionalities (basically able to speak with CNC and with nodes at the same time).
I don’t see any issue in allowing for a controller to be both PNC and MDSC at the same time.

BR
Daniele

From: ACTN [mailto:[e-mail]] On Behalf Of Arashmid Akhavain
Sent: venerdì 16 gennaio 2015 19:55
To: 윤빈영; Leeyoung; Igor Bryskin; [e-mail]<mailto:[e-mail]>
Subject: Re: [Actn] ACTN progress

I don’t think Young’s comment meant to collapse the 3-level model to a 2-level model. The interface design will be the same. But I think that is different from saying that CNC can bypass the MDSC and talk to PNC directly.

Regards,
Arashmid


From: ACTN [mailto:[e-mail]] On Behalf Of ???
Sent: 16 January 2015 03:23
To: Leeyoung; Igor Bryskin; [e-mail]<mailto:[e-mail]>
Subject: Re: [Actn] ACTN progress

Hi Young,

You newly define the term of “transparency (direct talk between CNC and PNC) ”.
It makes sense that the CNC directly interfaces with the PNC.
To me, it is like that MDSC is not used any more for this case.
So we can define two types of ACTN control hierarchy as follows.

- Three-level model: CNC-MDSC-PNC(current model)
– Two-level model: CNC-PNC(for the case that MDSC is transparent)

If it is right, the framework document should be modified to support the two-level model in terms of functionalities and architecture, as it currently describes only the three-level model.
In the current framework document, the PNC of the three-level model supports only two functionalities including “multi domain coordination function” and “virtualization/abstraction function”.
However, the PNC of the two-level model needs to support four functionalities for the direct interface to the CNC, as the CNC additionally requires “customer VN mapping function” and “virtual service coordination function”. Therefore, the document should be in line with the two-level model.

Correct me if I am wrong.

Sincerely yours

From: Leeyoung [mailto:[e-mail]]
Sent: Friday, January 16, 2015 2:00 AM
To: Igor Bryskin; 윤빈영; [e-mail]<mailto:[e-mail]>
Subject: Re: [Actn] ACTN progress

Hi Bin and Igor,

I agree with Igor on his short reply to Bin. Please see inline for my comment, Bin.

Thanks,
Young

From: Igor Bryskin [mailto:[e-mail]]
Sent: Thursday, January 15, 2015 7:54 AM
To: 윤빈영; Leeyoung; [e-mail]<mailto:[e-mail]>
Subject: RE: [Actn] ACTN progress

Hi Bin,
Your understanding is correct. Conceptually, the interfaces are the same. Practically, a given interface may support only a sub-set of functionality.

Igor

From: ACTN [mailto:[e-mail]] On Behalf Of ???
Sent: Wednesday, January 14, 2015 11:51 PM
To: Leeyoung; [e-mail]<mailto:[e-mail]>
Subject: Re: [Actn] ACTN progress


Hi Young,



I like to catch up with you.

So I like to translate your saying into my words for my clear understanding as follows.



For future ACTN work, we will keep the same architecture consisting of CNC-MDSC-PNC,

and the interfaces between them should be the same as Igor insists.

Each controller has the same functions conceptually,

but some functions may not be used depending on the type of controller(MDSC/PNC).



YOUNG>> Yes.



In order to implement the models(Provisioning, OAM, etc.) required for transport SDN,

ACTN will describe the interface of each controller based on the architecture of CNC-MDSC-PNC.

The interfaces between the controllers may be different practically due to some functions not used.



YOUNG>> Yes, but it would great if we can design the interfaces transparently so that one interface design will accommodate all functions.



We can say like the following if those above are true.

Some can implement a super(general) transport SDN controller to support all the functions,

while other can implement specific purposed(targeted) controllers such as PNC and MDSC.

For the former, the CMI is the same as the MPI.

For the latter, the CMI may not be the same as the MPI due to some functions not used.

ACTN will follow the latter for T-SDN implementation incorporating existing control systems like GMPLS and EMS/NMS.



YOUNG>> For the latter, we can design the MDSC-PNC interface as if CNC talking to PNC(s) directly, (which is termed as ‘transparency’) so that one interface design would fit to all cases. There may be some functions not used, which is fine, but we would say it is one interface design.



Correct me if there is any misunderstanding.



Thanks,

Bin

From: Leeyoung [mailto:[e-mail]]
Sent: Thursday, January 15, 2015 4:12 AM
To: [e-mail]<mailto:[e-mail]>
Subject: [Actn] ACTN progress

Hi All,

Just wanted to share some private emails exchanged among a limited interested parties in the past week with a permission with Igor.

In a nutshell, I think we are converging with a common view on ACTN interfaces and architecture. Please check the following email thread. Please comment if you have any question.

Thanks,
Young

From: Igor Bryskin [mailto:[e-mail]]
Sent: Thursday, January 08, 2015 2:13 PM
To: Leeyoung; Daniele Ceccarelli
Cc: AshwoodsmithPeter
Subject: RE: Recap this morning's call

Hi Young,
You’ve captured all pretty accurately. I nominate you for the ACTN scribe job :=)

Igor

From: Leeyoung [mailto:[e-mail]]
Sent: Thursday, January 08, 2015 3:09 PM
To: Igor Bryskin; Daniele Ceccarelli
Cc: AshwoodsmithPeter
Subject: Recap this morning's call

Hi Igor,

Thanks for this morning’s call. I just wanted to recap what was agreed upon. Please feel free to correct if anything needs to be corrected.

We have identified several models to be implemented in ACTN control hierarchy (CNC-MDSC-PNC). Among them are, but not limited to:


1.      Topology Model

2.      Provisioning Model

3.      Service Model

4.      OAM Model

5.      Client Mapping/Policy Model

There could be more to the list. We can identify and add later on if we will.

Now, with these models, different components (i.e., different controller type) will implement whatever relevant models and support its interfaces. For instance, PNC may need not support Client mapping/policy model while CNC may not need to support Provisioning model.

We also agree that MDSC can interface another MDSC or PNCs with transparency. MDSC should not be able to distinguish if it interfaces MDSC or PNCs (i.e., the same interface).

And you also said, CNC interfacing MDSC should be essentially the same interface as MDSC interfacing another MDSC or PNCs.

Let us start from here. Then we can discuss further.

Thanks,
Young