Re: [mpls] Concerns about ISD

[John E Drake <[e-mail]>]

Hi,

Comments inline below.

Yours Irrespectively,

John



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From: Tianran Zhou <[e-mail]>
Sent: Thursday, April 28, 2022 2:51 AM
To: John E Drake <jdrake=[e-mail]>; John E Drake <[e-mail]>; Tony Li <[e-mail]>
Cc: [e-mail]
Subject: RE: [mpls] Concerns about ISD

[External Email. Be cautious of content]

Hi John,

1. Do you only consider nrp?

[JD]  No, it was an example

 If so, there is no need for a generic ISD structure, which is very complex.

[JD]  There is no such thing as a generic ISD structure

And the nrp id we used in ipv6 is 32 bits.

[JD]  Presumably you have a proposal, but nothing has been standardized

 If we want to reuse this for consistent design (easy for interop), how do you want to encode it to ISD?

[JD]  That's up to a given solution to propose, but probably two LSEs

2. If we really worry about the MSD of SR, why not use BSID as a direct way to reduce the stack?

[JD]  Because it can't be mandated

Tianran

From: John E Drake [mailto:jdrake=[e-mail]]
Sent: Wednesday, April 27, 2022 9:06 PM
To: Tianran Zhou <[e-mail]<mailto:[e-mail]>>; John E Drake <[e-mail]<mailto:[e-mail]>>; Tony Li <[e-mail]<mailto:[e-mail]>>
Cc: [e-mail]<mailto:[e-mail]>
Subject: RE: [mpls] Concerns about ISD

Tianran,

If a network action is related to forwarding, e.g., its ancillary data indicates a network resource partition, I don't think defining its ancillary data to be post-stack makes sense.

Yours Irrespectively,

John



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From: mpls <[e-mail]<mailto:[e-mail]>> On Behalf Of Tianran Zhou
Sent: Wednesday, April 27, 2022 5:47 AM
To: John E Drake <jdrake=[e-mail]<mailto:jdrake=[e-mail]>>; Tony Li <[e-mail]<mailto:[e-mail]>>
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [mpls] Concerns about ISD

[External Email. Be cautious of content]

Hi Tony,

My native language is not English, I am sorry if I offended you in the following message. I did not mean to do so.
In my previous messages, I have presented my concerns on the ISD. And we discussed.
I think we can then work in the other way. We can demonstrate why the ISD is necessary and good.
That means, we figure out the cases which require ISD, the solution to implement ISD, and how this ISD implementation is better than a PSD implementation.
I acknowledge the motivation of using ISD for low stack exploration. But I do not see how one existing ISD proposal, say draft-kompella-mpls-mspl4fa, can work.

Regards,
Tianran

From: mpls [mailto:[e-mail]] On Behalf Of Tianran Zhou
Sent: Wednesday, April 13, 2022 9:17 AM
To: John E Drake <jdrake=[e-mail]<mailto:jdrake=[e-mail]>>; Tony Li <[e-mail]<mailto:[e-mail]>>
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [mpls] Concerns about ISD

Hi,

Comments in line.

Tianran



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From: mpls <[e-mail]<mailto:[e-mail]>> On Behalf Of Tianran Zhou
Sent: Tuesday, April 12, 2022 2:36 AM
To: Tony Li <[e-mail]<mailto:[e-mail]>>
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [mpls] Concerns about ISD

[External Email. Be cautious of content]

Hi Tony,

>>Pushing data to PSD and beyond the RLSD will cause systems to be excluded from the path or take a significant performance hit.

If I know the RLSD of each node, there are many ways to prevent some nodes from pushing data to PSD.

[JD]  Given that you *only* want to use PSD, what is the above sentence proposing?

ZTR> If you followed the past few emails, Tony misled people that PSD will hinder the interoperability. I just show you how PSD will not. According to your description below on the ISD process, it's the same as PSD somehow. I did not see the ISD advantage.

I would like to know how ISD could survive if the ISD exceed the RLSD?

[JD]  The correct term is Network Actions  Sub-stack (NAS).  To answer your question, a transit node will miss the NAS regardless of whether it contains in-stack data.  This is the point that Tony has been making for the past few email iterations

ZTR> Creating new terms does not help the community. I do not care the fancy term you created. Could you please point me out how many times Tony has clarified the ISD process? And where they are? I may have missed.
In my brain, Tony did not address any of my concerns on ISD, but only kept ignoring the fact I presented. It's not a good way for technique discussion.

Best,
Tianran

From: Tony Li [mailto:[e-mail]] On Behalf Of Tony Li
Sent: Tuesday, April 12, 2022 2:03 PM
To: Tianran Zhou <[e-mail]<mailto:[e-mail]>>
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [mpls] Concerns about ISD


Hi Tianran,

ZTR2> PSD can work with RLSD, I cannot see how it will hinder the interoperability.


Pushing data to PSD and beyond the RLSD will cause systems to be excluded from the path or take a significant performance hit.

Tony