Re: [Lsr] LSR WG Adoption Poll for "IS-IS Topology-Transparent Zone" - draft-chen-isis-ttz-11.txt

[Richard Li <[e-mail]>]

Hi Robert,

-😊 It was not meant to be a silver-bullet by saying “5G”. It happened that I have been discussing with folks on the design of the mobile backhaul/core/MEC.  Most of the designers and planners of the mobile backhaul/core/MEC do not work on routing technologies themselves, instead they choose and pick up some existing solutions provided by the IETF, and if they are not comfortable with the existing solutions, they use central controller/orchestrator and/or other management systems in a quasi-static config way.

Indeed, the WP you quoted does not indicate a need for zones. That said, you cannot deny that MEC is a set of inter-connected nodes, especially when being connected to the aggregation ring. Now the question is whether or not you allow such nodes to participate in routing. If you do, TTZ is a good candidate to reduce the internal topology and to turn MEC into a virtualized one; if you don’t, however, there is no space to discuss it.

Anyway, TTZ is aimed to be “experimental”.


Best regards,

Richard



From: Robert Raszuk <[e-mail]>
Sent: Wednesday, August 19, 2020 12:25 AM
To: Richard Li <[e-mail]>
Cc: Acee Lindem (acee) <acee=[e-mail]>; [e-mail]
Subject: Re: [Lsr] LSR WG Adoption Poll for "IS-IS Topology-Transparent Zone" - draft-chen-isis-ttz-11.txt

Hi Richard,

I understand that these days you say "5G" and you are done for any use case. :)

So I read this paper: https://www.etsi.org/images/files/ETSIWhitePapers/etsi_wp28_mec_in_5G_FINAL.pdf<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.etsi.org%2Fimages%2Ffiles%2FETSIWhitePapers%2Fetsi_wp28_mec_in_5G_FINAL.pdf&data=02%7C01%7Crichard.li%40futurewei.com%7C1a28b96b430246e2eaa208d8441111f2%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C1%7C637334187402121649&sdata=l7uwLpOhqEkY20ZsQgCv4N0Ce9JgVMG%2FskWQ1RdkjJ4%3D&reserved=0>

There is nothing there which would indicate a need for zone or even area separation to effectively deploy MEC. To me MEC data path can be constructed with a form of encapsulation in an arbitrary fashion. In fact I could say the more underlay walls you implement the harder it becomes to construct arbitrary MEC mesh.

At least for LSR WG if I were to justify any work here like TTZ I would explain why Multi access edge computing requires IGP/underlay type of separation and moreover why such separation can not be constructed with areas or levels.

Thx,
R.

On Wed, Aug 19, 2020 at 5:18 AM Richard Li <[e-mail]<mailto:[e-mail]>> wrote:
This is a use case:

The user plane of 5G is distributed, and MEC is deployed as part of the user plane to provide some functions at Access Aggregation Ring or Regional Aggregation Ring or at the border between Regional Aggregation Ring and the National Core. Using TTZ, MEC or part of it can be virtualized and topologically simplified. Note that the outside really doesn’t care about the internals of MEC.


Thanks,

Richard



From: Lsr <[e-mail]<mailto:[e-mail]>> On Behalf Of Robert Raszuk
Sent: Tuesday, August 18, 2020 2:25 PM
To: Acee Lindem (acee) <acee=[e-mail]<mailto:[e-mail]>>
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [Lsr] LSR WG Adoption Poll for "IS-IS Topology-Transparent Zone" - draft-chen-isis-ttz-11.txt

Dear WG,

The draft in question does not describe even a single practical use case.

While it describes the mechanics on how to construct the new model of the abstraction it fails to prove we need it.

Not everything which can be invented should be standardized or implemented therefore until the document extensively describes the real use cases with justification why use of areas may not be sufficient for such use cases I don't think LSR WG should adopt it.

Regards,
Robert.

On Tue, Aug 18, 2020 at 4:17 PM Acee Lindem (acee) <acee=[e-mail]<mailto:[e-mail]>> wrote:

Based on the discussions in the last meeting and on the mailing list regarding draft-chen-isis-ttz-11, the chairs feel that there are enough differences with draft-ietf-lsr-isis-area-proxy-03 and in the community to consider advancing it independently on the experimental track.

These differences include abstraction at arbitrary boundaries and IS-IS extensions for smooth transition to/from zone abstraction.

We are now starting an LSR WG adoption call for draft-chen-isis-ttz-11.txt. Please indicate your support or objection to adoption prior to Tuesday, September 2nd, 2020.

Thanks,
Acee and Chris

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