Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Acee Lindem (acee)]

The WG adoption call has completed and the document has significant support for 
adoption. I’m anticipating that we’ll have more than one algorithm document so 
it would be better to have a less generic name. For example, 
draft-ietf-lsr-flooding-topo-min-degree.txt. The replaces meta-data can be set 
independent of the WG document name so we have freedom here.

Thanks,
Acee

From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, May 15, 2020 at 3:40 PM
To: "lsr@ietf.org" 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Acee Lindem (acee)]

Hi Huaimo,

From: Huaimo Chen 
Date: Friday, June 5, 2020 at 9:03 PM
To: Acee Lindem , "lsr@ietf.org" 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

Hi Acee,

Thank you very much for your valuable comments.
My answers/explanations are inline below.

Best Regards,
Huaimo

From: Lsr  on behalf of Acee Lindem (acee) 

Sent: Friday, June 5, 2020 12:52 PM
To: lsr@ietf.org 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Speaking as WG Member:



Hi Authors,



I have a couple technical comments on the draft.



1.  The algorithm only computes a single graph with single path to each 
node. While I-D.ietf-lsr-dynamic-flooding failure and computation of an updated 
flooding topology, many of the other algorithms (both draft and proprietary) 
attempt to compute two or more paths to each node.
[HC]: The flooding topology (or say a graph) computed by the algorithm has at 
least two paths to each node. At step 4 of the algorithm on page 5 of the 
draft, for each node B that has only one path to it on the flooding topology 
(i.e., the Degree of node B is one) , another path is added to it. Thus the 
final flooding topology (or say graph) computed by the algorithm has  two or 
more paths to every node.

Ok – I see this now.





2.  Since this algorithm is slated for use as a distributed algorithm, all 
routers in the area must use the same value for MaxD or they may compute 
different flooding topologies. This is cannot be guaranteed by a single 
algorithm IANA value unless we allow some number of algorithm specific 
parameters to be advertised by the area leader (which might not be a bad idea).
[HC]: You are right. All the routers must use the same value for MaxD. We will 
update the draft for this accordingly. For now, MaxD has an initial value of 3 
(i.e., every router uses this initial value of 3 for MaxD).  The algorithm 
increases MaxD by one and restarts to compute the flooding topology with this 
new MaxD if it can not compute a flooding topology with the old MaxD. After 
some iterations in some cases, the flooding topology is computed. It is a good 
idea to pass some parameters from the area leader to every router when the 
leader advertises the algorithm number to every router.  MaxD can be one of the 
parameters.

3.   Similarly, the constraints in section 4.2 must be applied uniformly 
and different constraints would require new IANA algorithm allocation.
[HC]: You are right. All the routers must use the same constraints.  A new (or 
different) set of constraints need a new algorithm number. We will update the 
draft for this accordingly.



I see you’ve updated this in the latest.



Thanks,

Acee



Thanks,
Acee



From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, May 15, 2020 at 3:40 PM
To: "lsr@ietf.org" 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C1a7e82ec42fa40a9ad8e08d80970ea4c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637269727959858751=eG3iR27JyxGL6qCsqlMow47twBhMpf0%2BsgJo6Q9hBJg%3D=0>



Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Yingzhen,

Thank you very much for your support and comment.
My answer/explanation is inline below.

Best Regards,
Huaimo

From: Yingzhen Qu 
Sent: Friday, June 5, 2020 3:37 PM
To: Acee Lindem (acee) ; lsr@ietf.org 
; Huaimo Chen 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Hi,



I support adoption of this draft.



Hi Huaimo,



I have a question regarding the draft. At the end of section 3, it says if 
there is any change in the base topology, the flooding topology MUST be 
re-computed. So in case of a link failure in the base topo, it’s possible that 
the link is not part of the flooding topology (e.g. one of the multiple links 
between two nodes), it might be optimal if we can figure it out and save 
recalculation here.

[HC]: This will make sure that the flooding topologies computed by all the 
routers will be the same. If the algorithm does not compute a new flooding 
topology when a link that is not on the current flooding topology fails, we 
need prove that in any sequence of changes in base topology reaching to 
different LSDBs in different times the flooding topology computed by the 
algorithm on one router will be the same as the one computed by the algorithm 
on another router in this way.  After there is a proof, the optimized algorithm 
can be used.



Thanks,

Yingzhen



From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, June 5, 2020 at 10:09 AM
To: "lsr@ietf.org" 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
Resent-From: 



Speaking as WG Member:



Hi Authors,



I have a couple technical comments on the draft.



  1.  The algorithm only computes a single graph with single path to each node. 
While I-D.ietf-lsr-dynamic-flooding failure and computation of an updated 
flooding topology, many of the other algorithms (both draft and proprietary) 
attempt to compute two or more paths to each node.
  2.  Since this algorithm is slated for use as a distributed algorithm, all 
routers in the area must use the same value for MaxD or they may compute 
different flooding topologies. This is cannot be guaranteed by a single 
algorithm IANA value unless we allow some number of algorithm specific 
parameters to be advertised by the area leader (which might not be a bad idea).
  3.   Similarly, the constraints in section 4.2 must be applied uniformly and 
different constraints would require new IANA algorithm allocation.



Thanks,
Acee



From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, May 15, 2020 at 3:40 PM
To: "lsr@ietf.org" 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C41eead7b49484332128d08d80987e8b8%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637269826621073729=mScDoVdFmFXGhPmKPfq0jG5fgJub4Sb8abZ4%2BVVQzVk%3D=0>



Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Acee,

Thank you very much for your valuable comments.
My answers/explanations are inline below.

Best Regards,
Huaimo

From: Lsr  on behalf of Acee Lindem (acee) 

Sent: Friday, June 5, 2020 12:52 PM
To: lsr@ietf.org 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Speaking as WG Member:



Hi Authors,



I have a couple technical comments on the draft.



  1.  The algorithm only computes a single graph with single path to each node. 
While I-D.ietf-lsr-dynamic-flooding failure and computation of an updated 
flooding topology, many of the other algorithms (both draft and proprietary) 
attempt to compute two or more paths to each node.
[HC]: The flooding topology (or say a graph) computed by the algorithm has at 
least two paths to each node. At step 4 of the algorithm on page 5 of the 
draft, for each node B that has only one path to it on the flooding topology 
(i.e., the Degree of node B is one) , another path is added to it. Thus the 
final flooding topology (or say graph) computed by the algorithm has  two or 
more paths to every node.
  2.  Since this algorithm is slated for use as a distributed algorithm, all 
routers in the area must use the same value for MaxD or they may compute 
different flooding topologies. This is cannot be guaranteed by a single 
algorithm IANA value unless we allow some number of algorithm specific 
parameters to be advertised by the area leader (which might not be a bad idea).
[HC]: You are right. All the routers must use the same value for MaxD. We will 
update the draft for this accordingly. For now, MaxD has an initial value of 3 
(i.e., every router uses this initial value of 3 for MaxD).  The algorithm 
increases MaxD by one and restarts to compute the flooding topology with this 
new MaxD if it can not compute a flooding topology with the old MaxD. After 
some iterations in some cases, the flooding topology is computed. It is a good 
idea to pass some parameters from the area leader to every router when the 
leader advertises the algorithm number to every router.  MaxD can be one of the 
parameters.
  3.   Similarly, the constraints in section 4.2 must be applied uniformly and 
different constraints would require new IANA algorithm allocation.
[HC]: You are right. All the routers must use the same constraints.  A new (or 
different) set of constraints need a new algorithm number. We will update the 
draft for this accordingly.



Thanks,
Acee



From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, May 15, 2020 at 3:40 PM
To: "lsr@ietf.org" 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C1a7e82ec42fa40a9ad8e08d80970ea4c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637269727959858751=eG3iR27JyxGL6qCsqlMow47twBhMpf0%2BsgJo6Q9hBJg%3D=0>



Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Yingzhen Qu]

Hi Tony,

Thanks for jumping in and the explanation. I support the idea of tradeoffs 
between pefection and simplicity. Analysis about the change of topology can be 
tricky, especially when adding links, and for a distributed algorithm it’s more 
important to achieve a definitive result. Maybe it’s easier to optimize some 
cases in a centralized-mode, but we always need to consider benefit-cost ratio.

The text in the draft is “MUST be”, so I thought I’d ask to confirm.

Thanks,
Yingzhen

From: Tony Li  on behalf of "tony...@tony.li" 

Date: Friday, June 5, 2020 at 2:56 PM
To: Yingzhen Qu 
Cc: "Acee Lindem (acee)" , "lsr@ietf.org" 
, Huaimo Chen 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Hi,



I have a question regarding the draft. At the end of section 3, it says if 
there is any change in the base topology, the flooding topology MUST be 
re-computed. So in case of a link failure in the base topo, it’s possible that 
the link is not part of the flooding topology (e.g. one of the multiple links 
between two nodes), it might be optimal if we can figure it out and save 
recalculation here.


This comment isn’t specific to this algorithm, so you’ll pardon me if I jump in.

Always recomputing the flooding topology is always a safe thing to do and for 
the case of a distributed algorithm is probably the safest design choice.

Doing the analysis about the change is not exactly trivial and computing the 
flooding topology is not that hard.  We are typically not short of CPU cycles 
and recomputing the flooding topology is outside of the critical convergence 
window, so while there is some theoretical benefit, it’s not at all clear that 
it’s of great practical benefit.  But it is up to those specifying the 
algorithm.

Regards,
Tony



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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[tony . li]

Hi,


> I have a question regarding the draft. At the end of section 3, it says if 
> there is any change in the base topology, the flooding topology MUST be 
> re-computed. So in case of a link failure in the base topo, it’s possible 
> that the link is not part of the flooding topology (e.g. one of the multiple 
> links between two nodes), it might be optimal if we can figure it out and 
> save recalculation here.


This comment isn’t specific to this algorithm, so you’ll pardon me if I jump in.

Always recomputing the flooding topology is always a safe thing to do and for 
the case of a distributed algorithm is probably the safest design choice.

Doing the analysis about the change is not exactly trivial and computing the 
flooding topology is not that hard.  We are typically not short of CPU cycles 
and recomputing the flooding topology is outside of the critical convergence 
window, so while there is some theoretical benefit, it’s not at all clear that 
it’s of great practical benefit.  But it is up to those specifying the 
algorithm.

Regards,
Tony



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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Yingzhen Qu]

Hi,

I support adoption of this draft.

Hi Huaimo,

I have a question regarding the draft. At the end of section 3, it says if 
there is any change in the base topology, the flooding topology MUST be 
re-computed. So in case of a link failure in the base topo, it’s possible that 
the link is not part of the flooding topology (e.g. one of the multiple links 
between two nodes), it might be optimal if we can figure it out and save 
recalculation here.

Thanks,
Yingzhen

From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, June 5, 2020 at 10:09 AM
To: "lsr@ietf.org" 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
Resent-From: 

Speaking as WG Member:

Hi Authors,

I have a couple technical comments on the draft.


  1.  The algorithm only computes a single graph with single path to each node. 
While I-D.ietf-lsr-dynamic-flooding failure and computation of an updated 
flooding topology, many of the other algorithms (both draft and proprietary) 
attempt to compute two or more paths to each node.
  2.  Since this algorithm is slated for use as a distributed algorithm, all 
routers in the area must use the same value for MaxD or they may compute 
different flooding topologies. This is cannot be guaranteed by a single 
algorithm IANA value unless we allow some number of algorithm specific 
parameters to be advertised by the area leader (which might not be a bad idea).
  3.   Similarly, the constraints in section 4.2 must be applied uniformly and 
different constraints would require new IANA algorithm allocation.

Thanks,
Acee

From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, May 15, 2020 at 3:40 PM
To: "lsr@ietf.org" 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Cyingzhen.qu%40futurewei.com%7C548f8195e2c645d22c8308d8097321cf%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C1%7C637269737558376155=ZzzEb%2BAoqJIlp9eAtAnQ8CCgTqamuCYqcBCTeNOMhc0%3D=0>

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Acee Lindem (acee)]

Speaking as WG Member:

Hi Authors,

I have a couple technical comments on the draft.


  1.  The algorithm only computes a single graph with single path to each node. 
While I-D.ietf-lsr-dynamic-flooding failure and computation of an updated 
flooding topology, many of the other algorithms (both draft and proprietary) 
attempt to compute two or more paths to each node.
  2.  Since this algorithm is slated for use as a distributed algorithm, all 
routers in the area must use the same value for MaxD or they may compute 
different flooding topologies. This is cannot be guaranteed by a single 
algorithm IANA value unless we allow some number of algorithm specific 
parameters to be advertised by the area leader (which might not be a bad idea).
  3.   Similarly, the constraints in section 4.2 must be applied uniformly and 
different constraints would require new IANA algorithm allocation.

Thanks,
Acee

From: Lsr  on behalf of "Acee Lindem (acee)" 

Date: Friday, May 15, 2020 at 3:40 PM
To: "lsr@ietf.org" 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Kiran Makhijani]

Support WG adoption.
Regards,
Kiran

From: Lsr  On Behalf Of Acee Lindem (acee)
Sent: Friday, May 15, 2020 12:40 PM
To: lsr@ietf.org
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Yi Yang]

Support.


Yi

On 5/15/20 3:39 PM, Acee Lindem (acee) wrote:


This begins a 3 week (due to holidays) WG adoption call for the 
“Flooding Topology Computation Algorithm” draft. Please issue your 
support or objection to this list by 11:59 PM, UTC on June 5^th , 
2020. Here is a URL for your convenience.


https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee


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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Xuesong,

Thank you very much for your support and comments.
We will add more explanations in “Appendix A.  FT Computation Details 
through Example ” and brief the relation to other work.

Best Regards,
Huaimo

From: Lsr  on behalf of Gengxuesong (Geng Xuesong) 

Sent: Tuesday, June 2, 2020 8:42 AM
To: Acee Lindem (acee) ; lsr@ietf.org 

Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Hi,



I’ve read the draft and I think the draft is useful and ready for WG adoption.

By the way, when reading the draft, I feel a little difficult to understand the 
mathematical symbols in the draft, especially in the “Appendix A.  FT 
Computation Details through Example .” It will be appreciated if the authors 
could add more explanations about this.  And I believe some brief introduction 
about the relationship between this draft and other existing work in the WG 
will also be very helpful.



Best Regards

Xuesong



From: Lsr [mailto:lsr-boun...@ietf.org] On Behalf Of Acee Lindem (acee)
Sent: Saturday, May 16, 2020 3:40 AM
To: lsr@ietf.org
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7Cf69aa8eb9062482bf10408d806f27e66%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637266985864337874=nJrePFdWqQRTxOMhU0Lf538rH2sWCIPc036dI1Pvx4I%3D=0>



Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gengxuesong (Geng Xuesong)]

Hi,

I’ve read the draft and I think the draft is useful and ready for WG adoption.
By the way, when reading the draft, I feel a little difficult to understand the 
mathematical symbols in the draft, especially in the “Appendix A.  FT 
Computation Details through Example .” It will be appreciated if the authors 
could add more explanations about this.  And I believe some brief introduction 
about the relationship between this draft and other existing work in the WG 
will also be very helpful.

Best Regards
Xuesong

From: Lsr [mailto:lsr-boun...@ietf.org] On Behalf Of Acee Lindem (acee)
Sent: Saturday, May 16, 2020 3:40 AM
To: lsr@ietf.org
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huzhibo]

I support this adaption.It propose an algorithm for node to compute a flooding 
topology.It is useful for reduce flooding.

--
胡志波 Hu Zhibo
Mobile: +86-18618192287
Email: huzh...@huawei.com

发件人：Acee Lindem (acee) 
收件人：lsr 
时 间：2020-05-16 03:40:29
主 题：[Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Hi Huaimo

Thank you for answering my questions.

Replies in-line

On Sun, May 24, 2020 at 10:25 PM Huaimo Chen 
wrote:

> Hi Gyan,
>
> Thanks much for your comments and suggestions. My answers/explanations
> are inline below.
>
> Best Regards,
> Huaimo
> --
> *From:* Gyan Mishra 
> *Sent:* Friday, May 22, 2020 9:11 PM
> *To:* Huaimo Chen 
> *Cc:* Acee Lindem (acee) ; lsr@ietf.org 
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
> Hi Huaimo
>
> Thinking about physical topology a little further as with the FT algorithm
> it makes sense to decouple the FT from the physical however the overall
> coverage is based on those basic parameters of degree number of links and
> nodes as well as width and depth of the topology.
> [HC]: We may add/think more about physical topology and reduce/simplify
> the description about parameters in the draft.
>

Gyan>. Thank you I think that would be really helpful adding other
physical topologies other then full mesh and if you can do clos 3 tier and
leaf/spine would be great. Simplify parameter descriptions would be very
helpful.

>
> Thinking about it further the clos leaf spine DC style topology is much
> worse in terms of flooding due to physical topology that leafs don’t
> physical connection and are interconnected via the spine creating massive
> ECMP and overload of the spine super spine.  So the physical DC leaf spine
> topology really exacerbates the flooding due to the non full mesh nature of
> the topology.
> [HC]: You are right. The clos leaf spine topology is much worse. The
> algorithm in the draft can be used to compute FT for the clos leaf spine
> topology and reduce the number of links used for flooding significantly.
>

Gyan> Adding the other physical would help visualize how the algorithm
works with all topologies.  In reading the draft I did not get that the
algorithm would work for clos or leaf/spine so maybe need to add verbiage
to clarify.

>
> With a service provider core which is typically a mesh style multi tier
> multiple concentric circles mix of full and partial mesh and hub spoke type
> physical topologies.
>
> So with flooding with full mesh every node connects with every node so you
> don’t have an overload of flooding being funneled through a super spine as
> you do with a leaf spine DC architecture.  So in a full mesh which is the
> best case scenario for flooding perspective from my point of view which
> each node as root connects to all nodes and then you can iteratively grow
> the flooding scope and it’s pretty controlled and you can limit the
> redundant flooding.  When the physical topology changes to a much more
> partially meshed the ECMP paths grow astronomically as does the flooding
> and longer convergence time.
>
> So I think in the slide deck and draft look at scenario where their is
> tremendous ECMP from partial meshing and how the flood reduction algorithm
> improves the flooding and convergence.
> [HC]: They should have more scenarios including clos spine leafs. The
> reason for not having them in the draft is that "drawing" topology of clos
> spine leaf to illustrate the algorithm in details is very hard.
>
> Kind regards
>
> Gyan
>
> On Fri, May 22, 2020 at 8:41 PM Gyan Mishra  wrote:
>
> Hi Huaimo
>
> Thank you for the slide deck.  That really helps understand the algorithm..
>
>
> I will let you know if I have any questions.
>
> The goal of the algorithm is to speed up convergence by limiting the
> convergence scope and expanding out 1 link at a time until all nodes and
> links are part of the flood scope.  From the examples in the slide deck I
> did not see mentioned what is done with the dynamic flooding algorithm
> where when you have a meshed network in the slide 5 examples, how do you
> limit the flooding on redundant links duplicate flooding with the many
> meshed paths as you iteratively grow the FT nodes scope Cq().  I believe
> with the dynamic flooding it does a degree of 2 so 2 links between nodes.
>
> I think with clos spine leaf the mesh is much more intensive and
> problematic with ECMP then a circular topology nodal mesh that results in
> duplicate redundant flooding that slows down convergence.  With spine leaf
> it’s like an X horizontal width axis and then depth is spine to leaf
> links.  With spine leaf as you grow sideways and the spine expand the
> redundant ECMP grows and redundant flooding grows exponentially and is much
> worse then circular nodal mesh.
>
> Thank you
>
> Gyan
>
> On Fri, May 22, 2020 at 10:05 AM Huaimo Chen 
> wrote:
>
> Hi Gyan,
>
>     Thanks much for your

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Les & Tony

Please see my replies inline

On Wed, May 27, 2020 at 1:49 PM Les Ginsberg (ginsberg) 
wrote:

> Tony/Gyan –
>
>
>
> Please find my replies inline.
>
>
>
> *From:* Lsr  *On Behalf Of * tony...@tony.li
> *Sent:* Wednesday, May 20, 2020 8:48 AM
> *To:* Gyan Mishra 
> *Cc:* lsr@ietf.org; Huaimo Chen ; Acee Lindem
> (acee) 
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
>
>
> Hi Gyan,
>
>
>
>
>
> This is a much needed feature that operators have been needing for densely
> meshed topologies that commonly exist in data centers to accommodate very
> high bandwidth E-W traffic.
>
>
>
> Thank you.
>
>
>
> Please look at the feature description and it does seem to be exactly the
> same as this draft.  Please confirm.
>
>
>
>
>
> It would appear to be a different, proprietary, and unpublished algorithm..
>
>
>
>
> *[Les:] Yes, this is a different algorithm than either
> https://datatracker.ietf.org/doc/draft-chen-lsr-dynamic-flooding-algorithm/
> <https://datatracker.ietf.org/doc/draft-chen-lsr-dynamic-flooding-algorithm/>
> or  https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/
> <https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/>*
>
* <https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/>*
>
> *We are contemplating submitting a draft for this algorithm to the WG.*
>
> * Gyan> I think that would  be good for your customers so it’s not
> proprietary.*
>
>
>
>
>
> This will give us three different implementations, using three different
> algorithms, none of which will inter-operate.  Whee!!! :-(
>
>
>
>
>
> *[Les:] As I understand it, draft-chen only supports centralized mode –
> which is why it is Informational track and does not have interoperability
> concerns.*
>
> *Sarah/Tony - do you have plans to extend this to support distributed mode
> and then standardize it?*
>
>
>
> *At present there are no standard algorithm candidates which have achieved
> WG status – though that likely will change very soon.*
>
> *And the point of allowing multiple standardized algorithms to be defined
> was in the expectation that more than one might be proven useful.*
>
> * Gyan> So along those same lines in theory we could have hypothetically 3
> algorithms and all three on standards track which would give operators like
> Verizon and 3 options to pick from based on the physical topology use case.*
>
*Caveat would be - would vendors really want to develop other vendors
> options at a cost especially if there are more then two or rather keep
> their own option proprietary.  I think *
>
There maybe other features that you could get away with interoperability
> not being a concern but I think the flooding algorithm I would think would
> have to be the same for 2 vendors to be interoperable.
>
> There maybe other vendors due to industry demand have to get the feature
> deployed before it reaches standards vendor consensus with the IETF.
>
>
>
>
>
> Our implementation shipped last year.
>
>
>
> *[Les:] As did Cisco’s.*
>
>
>
>
>
> We are testing this feature and planning to deploy but wanted to ensure
> that this is the same as the draft on the standards track.
>
>
>
>
>
> It does not appear to be, but someone from Cisco should confirm.
>
>
>
> *[Les:] Confirmed.*
>
>
>
> *   Les*
>
>
>
> Tony
>
>
>
-- 

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[tony . li]

Les,


> We are contemplating submitting a draft for this algorithm to the WG.


We would welcome that.  

Does your algorithm have any relationship to 
https://tools.ietf.org/html/draft-allan-lsr-flooding-algorithm-00? 



> [Les:] As I understand it, draft-chen only supports centralized mode – which 
> is why it is Informational track and does not have interoperability concerns.
> Sarah/Tony - do you have plans to extend this to support distributed mode and 
> then standardize it?


Not at this time.  As we said during our presentation, we found debugging this 
already ‘challenging’ and morphing it to be distributed and deterministic in 
distributed mode doesn’t pass our sense of a beneficial cost/benefit ratio.

We have no objections if others want to take this on.  Centralized mode Just 
Works.


> And the point of allowing multiple standardized algorithms to be defined was 
> in the expectation that more than one might be proven useful.


Interoperability might also prove useful. :-)

Tony


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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Les Ginsberg (ginsberg)]

Tony/Gyan -

Please find my replies inline.

From: Lsr  On Behalf Of tony...@tony.li
Sent: Wednesday, May 20, 2020 8:48 AM
To: Gyan Mishra 
Cc: lsr@ietf.org; Huaimo Chen ; Acee Lindem (acee) 

Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Hi Gyan,



This is a much needed feature that operators have been needing for densely 
meshed topologies that commonly exist in data centers to accommodate very high 
bandwidth E-W traffic.

Thank you.


Please look at the feature description and it does seem to be exactly the same 
as this draft.  Please confirm.


It would appear to be a different, proprietary, and unpublished algorithm.

[Les:] Yes, this is a different algorithm than either 
https://datatracker.ietf.org/doc/draft-chen-lsr-dynamic-flooding-algorithm/ or  
https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

We are contemplating submitting a draft for this algorithm to the WG.



This will give us three different implementations, using three different 
algorithms, none of which will inter-operate.  Whee!!! :-(


[Les:] As I understand it, draft-chen only supports centralized mode - which is 
why it is Informational track and does not have interoperability concerns.
Sarah/Tony - do you have plans to extend this to support distributed mode and 
then standardize it?

At present there are no standard algorithm candidates which have achieved WG 
status - though that likely will change very soon.
And the point of allowing multiple standardized algorithms to be defined was in 
the expectation that more than one might be proven useful.



There maybe other vendors due to industry demand have to get the feature 
deployed before it reaches standards vendor consensus with the IETF.


Our implementation shipped last year.

[Les:] As did Cisco's.


We are testing this feature and planning to deploy but wanted to ensure that 
this is the same as the draft on the standards track.


It does not appear to be, but someone from Cisco should confirm.

[Les:] Confirmed.

   Les

Tony

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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Toy, Mehmet]

I support the adoption.
Thanks
Mehmet



*From:* Lsr  *On Behalf Of *Acee Lindem (acee)
*Sent:* Friday, May 15, 2020 3:40 PM
*To:* lsr@ietf.org
*Subject:*



This begins a 3 week (due to holidays) WG adoption call for the “Flooding
Topology Computation Algorithm” draft. Please issue your support or
objection to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL
for your convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/




Thanks,
Acee

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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Gyan,

Gyan> I know we are trying to adopt an flooding algorithm
and from my reading up on all proposed algorithms, the dynamic flooding seems 
to be geared towards Data Center  partial mesh high x ECMP leaf spine 
architecture, where redundant flooding is problematic using either centralized 
area leader or distributed flooding using same dynamic algorithm,  versus the 
call for adoption flood reduction algorithm seems to geared towards full mesh 
but from what I can tell would not be the preferred for clos multi tier DC leaf 
spine topology with high x ECMP paths.

[HC]: The algorithm in the call for adoption is also for (or say, gear towards) 
clos multi tier DC leaf spine topology with high x ECMP paths. In the Appendix 
of the draft, a full mess example topology of 5 nodes is used to illustrate the 
steps of the algorithm in some details. Using this topology is for easily 
"drawing" it and illustrating the steps of the algorithm. "Drawing" a clos 
multi tier DC leaf spine topology high x ECMP paths to illustrate the algorithm 
in details is very hard in the draft.

Best Regards,
Huaimo

From: Gyan Mishra 
Sent: Sunday, May 24, 2020 6:29 PM
To: Sarah Chen ; tony...@tony.li 
Cc: Acee Lindem (acee) ; Huaimo Chen 
; lsr@ietf.org 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

Hi Acee

Do you know if the dynamic flooding algorithm discussed during interim ietf by 
Sarah and Toni is the same as the one implemented by Cisco on Nexus platform or 
is Cisco’s Dynamic flooding a proprietary implementation?

Cisco’s flooding algorithm does seem almost identical to dynamic flooding..

Cisco Dynamic flooding - Nexus 9k

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.cisco.com%2Fc%2Fen%2Fus%2Fproducts%2Fcollateral%2Fswitches%2Fnexus-9000-series-switches%2Fwhite-paper-c11-743015.html=02%7C01%7Chuaimo.chen%40futurewei.com%7C427cee154ea74148fc8f08d80031f917%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637259561920543212=qVG4uwYPelL1syGzMViZSvOodKoWy2dlL1AyZ%2BljmB0%3D=0>


Dynamic Flooding - Arista - Sarah & Toni

https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ietf..org%2Fid%2Fdraft-chen-lsr-dynamic-flooding-algorithm-00.html=02%7C01%7Chuaimo.chen%40futurewei.com%7C427cee154ea74148fc8f08d80031f917%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637259561920553208=v400uLAa%2Fu3RwJlHfYhplTzR4sXVwMpCZA%2B%2BSM6adgI%3D=0>

Flood reduction- H Chen - WG adoption pending

https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-cc-lsr-flooding-reduction-08=02%7C01%7Chuaimo.chen%40futurewei.com%7C427cee154ea74148fc8f08d80031f917%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637259561920553208=ZA%2F1DXQYGsbJHynkM5V8bj6Y5VnuwM%2FHftO02nlmzLk%3D=0>


I know we are trying to adopt an flooding algorithm
and from my reading up on all proposed algorithms, the dynamic flooding seems 
to be geared towards Data Center  partial mesh high x ECMP leaf spine 
architecture, where redundant flooding is problematic using either centralized 
area leader or distributed flooding using same dynamic algorithm,  versus the 
call for adoption flood reduction algorithm seems to geared towards full mesh 
but from what I can tell would not be the preferred for clos multi tier DC leaf 
spine topology with high x ECMP paths.

Why would we not want to adopt the best algorithm that is best for both full 
mesh and non full mesh leaf spine topology algorithm that works for all 
physical topologies and adopt that draft.

Unless a one size fits all won’t work I would like to understand why one best 
solution draft we come up with for an FT algorithm for all possible physical 
topologies cannot be picked for WG adoption.

Why would we want to adopt multiple flooding algorithms?

Gyan

On Sat, May 23, 2020 at 4:43 PM Gyan Mishra 
mailto:hayabusa...@gmail.com>> wrote:


On Fri, May 22, 2020 at 9:02 PM mailto:tony...@tony.li>> wrote:

Hi Gyan,

I think with clos spine leaf the mesh is much more intensive and problematic 
with ECMP then a circular topology nodal mesh that results in duplicate 
redundant flooding that slows down convergence.  With spine leaf it’s like an X 
horizontal width axis and then depth is spine to leaf links.  With spine leaf 
as you grow sideways and the spine expand the redundant ECMP grows and 
redundant flooding grows exponentially and is much worse then circular nodal 
mesh.

One very nice thing about dynamic flooding is that it computes a flooding 
topology at the node level.  If the adjacency between A and B is on the 

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Gyan,

Thanks much for your questions. My answers/explanations are inline below.

Best Regards,
Huaimo

From: Gyan Mishra 
Sent: Friday, May 22, 2020 8:41 PM
To: Huaimo Chen 
Cc: Acee Lindem (acee) ; lsr@ietf.org 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

Hi Huaimo

Thank you for the slide deck.  That really helps understand the algorithm.

I will let you know if I have any questions.

The goal of the algorithm is to speed up convergence by limiting the 
convergence scope and expanding out 1 link at a time until all nodes and links 
are part of the flood scope.  From the examples in the slide deck I did not see 
mentioned what is done with the dynamic flooding algorithm where when you have 
a meshed network in the slide 5 examples, how do you limit the flooding on 
redundant links duplicate flooding with the many meshed paths as you 
iteratively grow the FT nodes scope Cq().  I believe with the dynamic flooding 
it does a degree of 2 so 2 links between nodes.
[HC]: The slide 5 example illustrates step 4 of the algorithm in section 4.1. 
When the algorithm reaches this step, all the nodes are  on the FT, but some of 
them may have degree of 1 (i.e., one link on the FT connected to the node). 
This step makes sure that every node on the FT has degree of at least 2.  It 
seems that the dynamic flooding expects the FT having its every node with 
degree of at least 2 for redundancy. In the Dynamic Flooding on Dense Graphs, 
link states will be flooded over the links on the FT. For example, for a node 
with degree of N (e.g., 3), when the node receives a link state from one link 
on the FT, it will flood the link state to the other N-1 (e.g., 3-1=2) links on 
the FT.

I think with clos spine leaf the mesh is much more intensive and problematic 
with ECMP then a circular topology nodal mesh that results in duplicate 
redundant flooding that slows down convergence.  With spine leaf it’s like an X 
horizontal width axis and then depth is spine to leaf links.  With spine leaf 
as you grow sideways and the spine expand the redundant ECMP grows and 
redundant flooding grows exponentially and is much worse then circular nodal 
mesh.
[HC]: In the slides, a full mess topology is used to illustrate the algorithm 
in some details. The algorithm can be used to compute FT for any other topology 
such as clos spine leaf. For topology with M (e.g., 100) parallel links between 
any pair of nodes X and Y, the algorithm will just add one link to the FT 
between X and Y, the other M - 1 (e.g., 100-1 = 99) links will not be added to 
the FT. Thus the link states will flood over only this one link between X and Y 
on the FT and will not flood over the other M - 1 (e..g., 100 - 1 = 99) links, 
which are not on the FT.

Thank you

Gyan

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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[tony . li]

Hi Gyan,


> Do you know if the dynamic flooding algorithm discussed during interim ietf 
> by Sarah and Toni is the same as the one implemented by Cisco on Nexus 
> platform or is Cisco’s Dynamic flooding a proprietary implementation?


It appears not to be.  Our algorithm is not limited to leaf-spine topologies 
and has been tested against numerous other dense and sparse topologies.


> Why would we not want to adopt the best algorithm that is best for both full 
> mesh and non full mesh leaf spine topology algorithm that works for all 
> physical topologies and adopt that draft.  


Proving that an algorithm is ‘optimal’ is going to be very difficult, both from 
a theoretical and market standpoint. As is frequently the case with IETF, we 
are proposing many ideas and trying to sort through them.


> Unless a one size fits all won’t work I would like to understand why one best 
> solution draft we come up with for an FT algorithm for all possible physical 
> topologies cannot be picked for WG adoption.
> 
> Why would we want to adopt multiple flooding algorithms?


Adoption does not imply that it will be standardized.  It merely means that 
it’s part of the working group’s effort.  It is up to the WG and the market to 
decide which algorithms we should pursue.  Some may be enhanced, some may be 
revised, and some may be discarded. We can also adopt all of them and let the 
market sort it out.  That’s probably not the optimal approach from a 
technological perspective, but making real decisions in the modern IETF is very 
hard.

Tony


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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Hi Acee

Do you know if the dynamic flooding algorithm discussed during interim ietf
by Sarah and Toni is the same as the one implemented by Cisco on Nexus
platform or is Cisco’s Dynamic flooding a proprietary implementation?

Cisco’s flooding algorithm does seem almost identical to dynamic flooding.

Cisco Dynamic flooding - Nexus 9k

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html


Dynamic Flooding - Arista - Sarah & Toni

https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html

Flood reduction- H Chen - WG adoption pending

https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08


I know we are trying to adopt an flooding algorithm
and from my reading up on all proposed algorithms, the dynamic flooding
seems to be geared towards Data Center  partial mesh high x ECMP leaf spine
architecture, where redundant flooding is problematic using either
centralized area leader or distributed flooding using same dynamic
algorithm,  versus the call for adoption flood reduction algorithm seems to
geared towards full mesh but from what I can tell would not be the
preferred for clos multi tier DC leaf spine topology with high x ECMP paths..

Why would we not want to adopt the best algorithm that is best for both
full mesh and non full mesh leaf spine topology algorithm that works for
all physical topologies and adopt that draft.

Unless a one size fits all won’t work I would like to understand why one
best solution draft we come up with for an FT algorithm for all possible
physical topologies cannot be picked for WG adoption.

Why would we want to adopt multiple flooding algorithms?

Gyan

On Sat, May 23, 2020 at 4:43 PM Gyan Mishra  wrote:

>
>
> On Fri, May 22, 2020 at 9:02 PM  wrote:
>
>>
>> Hi Gyan,
>>
>> I think with clos spine leaf the mesh is much more intensive and
>> problematic with ECMP then a circular topology nodal mesh that results in
>> duplicate redundant flooding that slows down convergence.  With spine leaf
>> it’s like an X horizontal width axis and then depth is spine to leaf
>> links.  With spine leaf as you grow sideways and the spine expand the
>> redundant ECMP grows and redundant flooding grows exponentially and is much
>> worse then circular nodal mesh.
>>
>>
>> One very nice thing about dynamic flooding is that it computes a flooding
>> topology at the node level.  If the adjacency between A and B is on the
>> flooding topology, then any single link between them may be used for
>> flooding.  If you have 128 way parallel links, this is an immediate 128x
>> improvement in flooding overhead.  What’s more, A and B do not need to
>> agree on which link they are using and can use different links, resulting
>> in an asymmetric situation, without any loss of correctness or performance.
>>
>
>Gyan>. Agreed.  The dynamic flooding really helps with X way ECMP
> prevalent in high density data center clos multi tier leaf spine parial
> mesh topologies that scale massive bandwidth breadth wise horizontally for
> E-W flows.
>
>>
>> Regards,
>> Tony
>>
>> --
>
> 
>
> *Gyan Mishra*
>
> *Network Solutions A**rchitect *
>
>
>
> *M 301 502-134713101 Columbia Pike *Silver Spring, MD
>
> --



*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Hi Huaimo

Thinking about physical topology a little further as with the FT algorithm
it makes sense to decouple the FT from the physical however the overall
coverage is based on those basic parameters of degree number of links and
nodes as well as width and depth of the topology.

Thinking about it further the clos leaf spine DC style topology is much
worse in terms of flooding due to physical topology that leafs don’t
physical connection and are interconnected via the spine creating massive
ECMP and overload of the spine super spine.  So the physical DC leaf spine
topology really exacerbates the flooding due to the non full mesh nature of
the topology.

With a service provider core which is typically a mesh style multi tier
multiple concentric circles mix of full and partial mesh and hub spoke type
physical topologies.

So with flooding with full mesh every node connects with every node so you
don’t have an overload of flooding being funneled through a super spine as
you do with a leaf spine DC architecture.  So in a full mesh which is the
best case scenario for flooding perspective from my point of view which
each node as root connects to all nodes and then you can iteratively grow
the flooding scope and it’s pretty controlled and you can limit the
redundant flooding.  When the physical topology changes to a much more
partially meshed the ECMP paths grow astronomically as does the flooding
and longer convergence time.

So I think in the slide deck and draft look at scenario where their is
tremendous ECMP from partial meshing and how the flood reduction algorithm
improves the flooding and convergence.

Kind regards

Gyan

On Fri, May 22, 2020 at 8:41 PM Gyan Mishra  wrote:

> Hi Huaimo
>
> Thank you for the slide deck.  That really helps understand the algorithm..
>
>
> I will let you know if I have any questions.
>
> The goal of the algorithm is to speed up convergence by limiting the
> convergence scope and expanding out 1 link at a time until all nodes and
> links are part of the flood scope.  From the examples in the slide deck I
> did not see mentioned what is done with the dynamic flooding algorithm
> where when you have a meshed network in the slide 5 examples, how do you
> limit the flooding on redundant links duplicate flooding with the many
> meshed paths as you iteratively grow the FT nodes scope Cq().  I believe
> with the dynamic flooding it does a degree of 2 so 2 links between nodes.
>
> I think with clos spine leaf the mesh is much more intensive and
> problematic with ECMP then a circular topology nodal mesh that results in
> duplicate redundant flooding that slows down convergence.  With spine leaf
> it’s like an X horizontal width axis and then depth is spine to leaf
> links.  With spine leaf as you grow sideways and the spine expand the
> redundant ECMP grows and redundant flooding grows exponentially and is much
> worse then circular nodal mesh.
>
> Thank you
>
> Gyan
>
> On Fri, May 22, 2020 at 10:05 AM Huaimo Chen 
> wrote:
>
>> Hi Gyan,
>>
>> Thanks much for your questions. My answers/explanations are inline
>> below.
>>
>> Best Regards,
>> Huaimo
>> --
>> *From:* Gyan Mishra 
>> *Sent:* Thursday, May 21, 2020 10:13 PM
>> *To:* Acee Lindem (acee) 
>> *Cc:* Huaimo Chen ; lsr@ietf.org > >
>> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
>> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>>
>>
>> I think for both drafts it would be good to have a stick diagram at a
>> minimum.
>> [HC]: A diagram for illustrating the steps of the algorithm is in
>> Appendix.
>> I majored in EE with math  minor and both drafts are hard to follow
>> without a diagram with labels showing the exact topology examples.
>>
>> Four main topologies - full mesh, partial mesh and leaf spine ( 2 tier)
>> and CLOS ( 3 tier) - real world scenario’s.
>>
>> From the interim meeting was their a slide deck visual topology shared?
>> [HC]: The set of slides presented in IETF 105 is attached.
>>
>> That would help.
>>
>> https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08
>> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-cc-lsr-flooding-reduction-08=02%7C01%7Chuaimo.chen%40futurewei.com%7Cc9f9e8ddb76b406057d208d7fdf5cb4e%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257104446371900=glKNEHI0pmavkJwY%2BykW0%2BArX10F74JP0WMEvG6FY88%3D=0>
>>
>> 4.1
>>
>> Step 1 - Build Cq candidate queue
>>
>> For each node B on FT whose D is one (from minimum to maximum
>>node ID), find a link L attached to B such that L's remote node R
>

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[tony . li]

Hi Gyan,

> I think with clos spine leaf the mesh is much more intensive and problematic 
> with ECMP then a circular topology nodal mesh that results in duplicate 
> redundant flooding that slows down convergence.  With spine leaf it’s like an 
> X horizontal width axis and then depth is spine to leaf links.  With spine 
> leaf as you grow sideways and the spine expand the redundant ECMP grows and 
> redundant flooding grows exponentially and is much worse then circular nodal 
> mesh.  

One very nice thing about dynamic flooding is that it computes a flooding 
topology at the node level.  If the adjacency between A and B is on the 
flooding topology, then any single link between them may be used for flooding.  
If you have 128 way parallel links, this is an immediate 128x improvement in 
flooding overhead.  What’s more, A and B do not need to agree on which link 
they are using and can use different links, resulting in an asymmetric 
situation, without any loss of correctness or performance. 

Regards,
Tony

___
Lsr mailing list
Lsr@ietf.org
https://www.ietf.org/mailman/listinfo/lsr

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Hi Huaimo

Thank you for the slide deck.  That really helps understand the algorithm.

I will let you know if I have any questions.

The goal of the algorithm is to speed up convergence by limiting the
convergence scope and expanding out 1 link at a time until all nodes and
links are part of the flood scope.  From the examples in the slide deck I
did not see mentioned what is done with the dynamic flooding algorithm
where when you have a meshed network in the slide 5 examples, how do you
limit the flooding on redundant links duplicate flooding with the many
meshed paths as you iteratively grow the FT nodes scope Cq().  I believe
with the dynamic flooding it does a degree of 2 so 2 links between nodes.

I think with clos spine leaf the mesh is much more intensive and
problematic with ECMP then a circular topology nodal mesh that results in
duplicate redundant flooding that slows down convergence.  With spine leaf
it’s like an X horizontal width axis and then depth is spine to leaf
links.  With spine leaf as you grow sideways and the spine expand the
redundant ECMP grows and redundant flooding grows exponentially and is much
worse then circular nodal mesh.

Thank you

Gyan

On Fri, May 22, 2020 at 10:05 AM Huaimo Chen 
wrote:

> Hi Gyan,
>
> Thanks much for your questions. My answers/explanations are inline
> below.
>
> Best Regards,
> Huaimo
> --
> *From:* Gyan Mishra 
> *Sent:* Thursday, May 21, 2020 10:13 PM
> *To:* Acee Lindem (acee) 
> *Cc:* Huaimo Chen ; lsr@ietf.org 
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
> I think for both drafts it would be good to have a stick diagram at a
> minimum.
> [HC]: A diagram for illustrating the steps of the algorithm is in Appendix.
> I majored in EE with math  minor and both drafts are hard to follow
> without a diagram with labels showing the exact topology examples.
>
> Four main topologies - full mesh, partial mesh and leaf spine ( 2 tier)
> and CLOS ( 3 tier) - real world scenario’s.
>
> From the interim meeting was their a slide deck visual topology shared?
> [HC]: The set of slides presented in IETF 105 is attached.
>
> That would help.
>
> https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-cc-lsr-flooding-reduction-08=02%7C01%7Chuaimo.chen%40futurewei.com%7Cc9f9e8ddb76b406057d208d7fdf5cb4e%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257104446371900=glKNEHI0pmavkJwY%2BykW0%2BArX10F74JP0WMEvG6FY88%3D=0>
>
> 4.1
>
> Step 1 - Build Cq candidate queue
>
> For each node B on FT whose D is one (from minimum to maximum
>node ID), find a link L attached to B such that L's remote node R
>has minimum D and ID, add link L between B and R into FT and
>increase B's D and R's D by one.  Return FT.
>
> My interpretation is the algorithm an iterative loop and starts with any
> node in the candidate list so could start from edge and work left to right
> or vice versa.  For loop to build FT from Cq = with each node B with
> directly attached node R via link L.  Increment node B from Cq until the FT
> is build for all nodes.  Instead of starting with a wide diameter FT
> matching physical topology we start micro topology with D=1 and go node by
> node.
> [HC]: This (For each node B on FT  Return FT.) is an iterative loop
> after every node is added to FT. This loop connects each node whose D = 1
> (i.e., there is only one link attached to it on FT) to a node through a
> link on FT (i.e., add the link to FT) to make every node on FT to have its
> D > 1. Page 5 of the attached slides shows some details for this loop.
>
> 4.2
>
> 1.  Finding and removing the first element with node A in Cq that is
>not on FT and one PH's D in PHs < MaxD and PH's D < PH's ConMaxD.
>
>If A is root R0, then add the element into FT
>
>otherwise  (i.e., A != R0 with one PH's D in PHs < MaxD and PH's
>   D < PH's ConMaxD.  Assume that PH is the first one in PHs
>   whose D < MaxD and PH's D < PH's ConMaxD), PH's D++, and add A
>   with D = 1 and PHs = {PH} into FT.
>
>Note:  if there is no element with a node in Cq satisfying the
>   conditions, then algorithm may be restarted from R0, ++MaxD,
>   Cq = {(R0,D=0,PHs = { })}, FT = { };
>
> This is similar to 4.1 with micro topology with 2 directly connected nodes
> [HC]: It is similar to 1. in section 4.1.
>
> https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Gyan,

Thanks much for your suggestion.

Gyan> It maybe a good idea for both documents to reference each other as to 
how they play together or  in some respects if any provide a homogeneous 
complete holistic solution for flooding problem being solved.

[HC]: I will add the reference in the draft.

Best Regards,
Huaimo

From: Gyan Mishra 
Sent: Thursday, May 21, 2020 1:51 PM
To: Huaimo Chen 
Cc: Acee Lindem (acee) ; lsr@ietf.org 

Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



On Thu, May 21, 2020 at 11:01 AM Huaimo Chen 
mailto:huaimo.c...@futurewei.com>> wrote:
Hi Gyan,

Thanks much for your questions.

 Gyan> How does this draft compare to the WG LC draft for flood reduction.  
Would they be two eventual standard options in the operators toolbox  or 
competing features for optimized flood reduction. Would having two flood 
reduction features standardized versus one default IGP flood reduction feature 
be confusing for operators.  Just as it was confusing to me.
https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7Ce0f4766963da47bb3ba608d7fdaf9134%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256802824693892=4vWmUdR%2BbXWXgjyBAw62Ig%2BxUyKPuq6uucKbrfbNv5w%3D=0>

[HC]: This draft plus the draft for flooding reduction can provide two 
modes of flooding reductions (i.e., centralized mode and distributed mode). The 
latter describes the two modes, but does not include any flooding topology 
computation algorithm for the distributed mode. The former proposes a flooding 
topology computation algorithm to be used in the distributed mode.

   Gyan> It maybe a good idea for both documents to reference each other as to 
how they play together or  in some respects if any provide a homogeneous 
complete holistic solution for flooding problem being solved.

In my opinion it may not be a bad idea even to combine both drafts so the 
solution is complete and holistic.  This will also make the overall 
specification flow nicely.

I know that efforts were made by LSR to have a common IGP solution, however 
there are many inherent differences between ISIS and OSPF that from IGP Link 
state protocol perspective you can treat like apples to apples but really it’s 
apples and oranges.  Maybe it might we wise to have separate draft for both and 
have references linking together as the same algorithm concept and 
mathematically however the actual code implementation would vary as the LSDB 
link state data structures are completely different.

Later = Dynamic flooding = 2 modes Centralized leader based and distributed

https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7Ce0f4766963da47bb3ba608d7fdaf9134%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256802824693892=4vWmUdR%2BbXWXgjyBAw62Ig%2BxUyKPuq6uucKbrfbNv5w%3D=0>

This later draft per section excerpt provides both centralized and distributed 
algorithm see below


6.4<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-ietf-lsr-dynamic-flooding-05%23section-6.4=02%7C01%7Chuaimo.chen%40futurewei.com%7Ce0f4766963da47bb3ba608d7fdaf9134%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256802824703852=FvMPjTxl622QWR0mgEZFUlnwM5rGlRKKdTWSTjPXcBs%3D=0>.
  Area Leader Responsibilities

   If the Area Leader operates in centralized mode, it MUST advertise
   algorithm 0 in its Area Leader Sub-TLV.  In order for Dynamic
   Flooding to be enabled it also MUST compute and advertise a flooding
   topology for the area.  The Area Leader may update the flooding
   topology at any time, however, it should not destabilize the network
   with undue or overly frequent topology changes.  If the Area Leader
   operates in centralized mode and needs to advertise a new flooding
   topology, it floods the new flooding topology on both the new and old
   flooding topologies.

   If the Area Leader operates in distributed mode, it MUST advertise a
   non-zero algorithm in its Area Leader Sub-TLV.

   When the Area Leader advertises algorithm 0 in its Area Leader Sub-
   TLV and does not advertise a flooding topology, Dynamic Flooding is
   disabled for the area.  Note this applies whether the Area Leader
   intends to operate in centralized mode or in distributed mode.

   Note that once Dynamic Flooding is enabled, disabling it risks
   destabilizing the network.

6.5<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-ietf-lsr-dynamic-flooding-05

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Great Thanks Sarah!!

Gyan

On Thu, May 21, 2020 at 10:59 PM Sarah Chen  wrote:

> Hi, Gyan,
>
> I presented
> https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html in
> the last IETF. You may find the slides below helpful in understanding the
> algorithm:
>
>
> https://datatracker.ietf.org/meeting/interim-2020-lsr-01/materials/slides-interim-2020-lsr-01-sessa-2-dynamic-flooding-algo-sarah.pdf
>
> Thanks,
> Sarah
>
> On Thu, May 21, 2020 at 7:32 PM Gyan Mishra  wrote:
>
>>
>> I see the diagrams Appendix A -  reviewing
>>
>> Thanks
>>
>> Gyan
>>
>
>> On Thu, May 21, 2020 at 10:13 PM Gyan Mishra 
>> wrote:
>>
>
>>> I think for both drafts it would be good to have a stick diagram at a
>>> minimum.
>>>
>>> I majored in EE with math  minor and both drafts are hard to follow
>>> without a diagram with labels showing the exact topology examples.
>>>
>>> Four main topologies - full mesh, partial mesh and leaf spine ( 2 tier)
>>> and CLOS ( 3 tier) - real world scenario’s.
>>>
>>> From the interim meeting was their a slide deck visual topology shared?
>>>
>>> That would help.
>>>
>>> https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08
>>>
>>> 4.1
>>>
>>> Step 1 - Build Cq candidate queue
>>>
>>> For each node B on FT whose D is one (from minimum to maximum
>>>node ID), find a link L attached to B such that L's remote node R
>>>has minimum D and ID, add link L between B and R into FT and
>>>increase B's D and R's D by one.  Return FT.
>>>
>>> My interpretation is the algorithm an iterative loop and starts with any
>>> node in the candidate list so could start from edge and work left to right
>>> or vice versa.  For loop to build FT from Cq = with each node B with
>>> directly attached node R via link L.  Increment node B from Cq until the FT
>>> is build for all nodes.  Instead of starting with a wide diameter FT
>>> matching physical topology we start micro topology with D=1 and go node by
>>> node.
>>>
>>> 4.2
>>>
>>> 1.  Finding and removing the first element with node A in Cq that is
>>>not on FT and one PH's D in PHs < MaxD and PH's D < PH's ConMaxD..
>>>
>>>If A is root R0, then add the element into FT
>>>
>>>otherwise  (i.e., A != R0 with one PH's D in PHs < MaxD and PH's
>>>   D < PH's ConMaxD.  Assume that PH is the first one in PHs
>>>   whose D < MaxD and PH's D < PH's ConMaxD), PH's D++, and add A
>>>   with D = 1 and PHs = {PH} into FT.
>>>
>>>Note:  if there is no element with a node in Cq satisfying the
>>>   conditions, then algorithm may be restarted from R0, ++MaxD,
>>>   Cq = {(R0,D=0,PHs = { })}, FT = { };
>>>
>>> This is similar to 4.1 with micro topology with 2 directly connected
>>> nodes
>>>
>>> https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html
>>>
>>> My interpretation of the algorithm from the verbiage.
>>>
>>> So this draft starts in the middle of the topology and is geared towards
>>> leaf spine 2 or 3 tier clos topology.
>>>
>>> For this one we build the bi graph so that could be leaf connected to
>>> two spines or spine connected to two leafs and iteratively build out the FT
>>> topology 3 node arch  spine leaf spine or leaf spine leaf.
>>>
>>> Kind regards
>>>
>>> Gyan
>>>
>>
>>> On Thu, May 21, 2020 at 7:01 PM Acee Lindem (acee) 
>>> wrote:
>>>
>> Hi Gyan,
>>>>
>>>>
>>>>
>>>> *From: *Gyan Mishra 
>>>> *Date: *Thursday, May 21, 2020 at 4:20 PM
>>>> *To: *Acee Lindem 
>>>> *Cc: *Huaimo Chen , "lsr@ietf.org" <
>>>> lsr@ietf.org>
>>>> *Subject: *Re: [Lsr] Flooding Topology Computation Algorithm -
>>>> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Yes and I have started reviewing the LSR mail archives as I am late in
>>>> the discussion for this.
>>>>
>>>>
>>>>
>>>> If you have link to any particular dates in the archives would be
>>>> help

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Sarah Chen]

Hi, Gyan,

I presented
https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html in
the last IETF. You may find the slides below helpful in understanding the
algorithm:

https://datatracker.ietf.org/meeting/interim-2020-lsr-01/materials/slides-interim-2020-lsr-01-sessa-2-dynamic-flooding-algo-sarah.pdf

Thanks,
Sarah

On Thu, May 21, 2020 at 7:32 PM Gyan Mishra  wrote:

>
> I see the diagrams Appendix A -  reviewing
>
> Thanks
>
> Gyan
>
> On Thu, May 21, 2020 at 10:13 PM Gyan Mishra 
> wrote:
>
>>
>> I think for both drafts it would be good to have a stick diagram at a
>> minimum.
>>
>> I majored in EE with math  minor and both drafts are hard to follow
>> without a diagram with labels showing the exact topology examples.
>>
>> Four main topologies - full mesh, partial mesh and leaf spine ( 2 tier)
>> and CLOS ( 3 tier) - real world scenario’s.
>>
>> From the interim meeting was their a slide deck visual topology shared?
>>
>> That would help.
>>
>> https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08
>>
>> 4.1
>>
>> Step 1 - Build Cq candidate queue
>>
>> For each node B on FT whose D is one (from minimum to maximum
>>node ID), find a link L attached to B such that L's remote node R
>>has minimum D and ID, add link L between B and R into FT and
>>increase B's D and R's D by one.  Return FT.
>>
>> My interpretation is the algorithm an iterative loop and starts with any
>> node in the candidate list so could start from edge and work left to right
>> or vice versa.  For loop to build FT from Cq = with each node B with
>> directly attached node R via link L.  Increment node B from Cq until the FT
>> is build for all nodes.  Instead of starting with a wide diameter FT
>> matching physical topology we start micro topology with D=1 and go node by
>> node.
>>
>> 4.2
>>
>> 1.  Finding and removing the first element with node A in Cq that is
>>not on FT and one PH's D in PHs < MaxD and PH's D < PH's ConMaxD.
>>
>>If A is root R0, then add the element into FT
>>
>>otherwise  (i.e., A != R0 with one PH's D in PHs < MaxD and PH's
>>   D < PH's ConMaxD.  Assume that PH is the first one in PHs
>>   whose D < MaxD and PH's D < PH's ConMaxD), PH's D++, and add A
>>   with D = 1 and PHs = {PH} into FT.
>>
>>Note:  if there is no element with a node in Cq satisfying the
>>   conditions, then algorithm may be restarted from R0, ++MaxD,
>>   Cq = {(R0,D=0,PHs = { })}, FT = { };
>>
>> This is similar to 4.1 with micro topology with 2 directly connected
>> nodes
>>
>> https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html
>>
>> My interpretation of the algorithm from the verbiage.
>>
>> So this draft starts in the middle of the topology and is geared towards
>> leaf spine 2 or 3 tier clos topology.
>>
>> For this one we build the bi graph so that could be leaf connected to two
>> spines or spine connected to two leafs and iteratively build out the FT
>> topology 3 node arch  spine leaf spine or leaf spine leaf.
>>
>> Kind regards
>>
>> Gyan
>>
>> On Thu, May 21, 2020 at 7:01 PM Acee Lindem (acee) 
>> wrote:
>>
>>> Hi Gyan,
>>>
>>>
>>>
>>> *From: *Gyan Mishra 
>>> *Date: *Thursday, May 21, 2020 at 4:20 PM
>>> *To: *Acee Lindem 
>>> *Cc: *Huaimo Chen , "lsr@ietf.org" <
>>> lsr@ietf.org>
>>> *Subject: *Re: [Lsr] Flooding Topology Computation Algorithm -
>>> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>>>
>>>
>>>
>>>
>>>
>>> Yes and I have started reviewing the LSR mail archives as I am late in
>>> the discussion for this.
>>>
>>>
>>>
>>> If you have link to any particular dates in the archives would be
>>> helpful.
>>>
>>>
>>>
>>> No – it was more an “evolution” than an “epiphany”.
>>>
>>>
>>>
>>> That sums up all the questions I have so if all answered in the archives
>>> then I am all set.
>>>
>>>
>>>
>>> I support the draft moving forward as flood reduction is a much needed
>>> feature.
>>>
>>>
>>>
>>> I think overall both drafts will really help large data centers with any
>>> overlay underlay vxlan spine leaf 

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

I think for both drafts it would be good to have a stick diagram at a
minimum.

I majored in EE with math  minor and both drafts are hard to follow without
a diagram with labels showing the exact topology examples.

Four main topologies - full mesh, partial mesh and leaf spine ( 2 tier) and
CLOS ( 3 tier) - real world scenario’s.

>From the interim meeting was their a slide deck visual topology shared?

That would help.

https://datatracker.ietf.org/doc/html/draft-cc-lsr-flooding-reduction-08

4.1

Step 1 - Build Cq candidate queue

For each node B on FT whose D is one (from minimum to maximum
   node ID), find a link L attached to B such that L's remote node R
   has minimum D and ID, add link L between B and R into FT and
   increase B's D and R's D by one.  Return FT.

My interpretation is the algorithm an iterative loop and starts with any
node in the candidate list so could start from edge and work left to right
or vice versa.  For loop to build FT from Cq = with each node B with
directly attached node R via link L.  Increment node B from Cq until the FT
is build for all nodes.  Instead of starting with a wide diameter FT
matching physical topology we start micro topology with D=1 and go node by
node.

4.2

1.  Finding and removing the first element with node A in Cq that is
   not on FT and one PH's D in PHs < MaxD and PH's D < PH's ConMaxD.

   If A is root R0, then add the element into FT

   otherwise  (i.e., A != R0 with one PH's D in PHs < MaxD and PH's
  D < PH's ConMaxD.  Assume that PH is the first one in PHs
  whose D < MaxD and PH's D < PH's ConMaxD), PH's D++, and add A
  with D = 1 and PHs = {PH} into FT.

   Note:  if there is no element with a node in Cq satisfying the
  conditions, then algorithm may be restarted from R0, ++MaxD,
  Cq = {(R0,D=0,PHs = { })}, FT = { };

This is similar to 4.1 with micro topology with 2 directly connected nodes

https://www.ietf.org/id/draft-chen-lsr-dynamic-flooding-algorithm-00.html

My interpretation of the algorithm from the verbiage.

So this draft starts in the middle of the topology and is geared towards
leaf spine 2 or 3 tier clos topology.

For this one we build the bi graph so that could be leaf connected to two
spines or spine connected to two leafs and iteratively build out the FT
topology 3 node arch  spine leaf spine or leaf spine leaf.

Kind regards

Gyan

On Thu, May 21, 2020 at 7:01 PM Acee Lindem (acee)  wrote:

> Hi Gyan,
>
>
>
> *From: *Gyan Mishra 
> *Date: *Thursday, May 21, 2020 at 4:20 PM
> *To: *Acee Lindem 
> *Cc: *Huaimo Chen , "lsr@ietf.org" <
> lsr@ietf.org>
> *Subject: *Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
>
>
> Yes and I have started reviewing the LSR mail archives as I am late in the
> discussion for this.
>
>
>
> If you have link to any particular dates in the archives would be helpful..
>
>
>
> No – it was more an “evolution” than an “epiphany”.
>
>
>
> That sums up all the questions I have so if all answered in the archives
> then I am all set.
>
>
>
> I support the draft moving forward as flood reduction is a much needed
> feature.
>
>
>
> I think overall both drafts will really help large data centers with any
> overlay underlay vxlan spine leaf meshed CLOS highly meshed topology that
> scales out horizontally with a large spine footprint - this is a much much
> needed feature.  This also helps eliminate complexity of the workaround of
> using BGP in the underlay which to me adds tremendous complexity.
>
>
>
> Here is the other recently presented dynamic flooding draft.
>
>
>
> https://datatracker.ietf.org/doc/draft-chen-lsr-dynamic-flooding-algorithm/
>
>
>
> You can see they both make use of the dynamic flooding infra in
> https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/
>
>
>
> Thanks,
>
> Acee
>
>
>
>
>
>
>
>
>
> Kind regards
>
>
>
> Gyan
>
>
>
> On Thu, May 21, 2020 at 4:07 PM Acee Lindem (acee)  wrote:
>
> Speaking as WG Co-chair:
>
>
>
> Hi Gyan,
>
>
>
> I guess you’ve joined this discussion late. It might be a good idea to
> review the LSR mailing list archives.
>
>
>
> *From: *Gyan Mishra 
> *Date: *Thursday, May 21, 2020 at 1:51 PM
> *To: *Huaimo Chen 
> *Cc: *Acee Lindem , "lsr@ietf.org" 
> *Subject: *Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
>
>
>
>
> On Thu, May 21, 2020 at 11:01 AM Huaimo Chen 
> wrote:
>
> Hi Gyan,
>
>
>
> Thanks much for your quest

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Acee Lindem (acee)]

Hi Gyan,

From: Gyan Mishra 
Date: Thursday, May 21, 2020 at 4:20 PM
To: Acee Lindem 
Cc: Huaimo Chen , "lsr@ietf.org" 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


Yes and I have started reviewing the LSR mail archives as I am late in the 
discussion for this.

If you have link to any particular dates in the archives would be helpful.

No – it was more an “evolution” than an “epiphany”.

That sums up all the questions I have so if all answered in the archives then I 
am all set.

I support the draft moving forward as flood reduction is a much needed feature.

I think overall both drafts will really help large data centers with any 
overlay underlay vxlan spine leaf meshed CLOS highly meshed topology that 
scales out horizontally with a large spine footprint - this is a much much 
needed feature.  This also helps eliminate complexity of the workaround of 
using BGP in the underlay which to me adds tremendous complexity.

Here is the other recently presented dynamic flooding draft.

https://datatracker.ietf.org/doc/draft-chen-lsr-dynamic-flooding-algorithm/

You can see they both make use of the dynamic flooding infra in 
https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/

Thanks,
Acee




Kind regards

Gyan

On Thu, May 21, 2020 at 4:07 PM Acee Lindem (acee) 
mailto:a...@cisco.com>> wrote:
Speaking as WG Co-chair:

Hi Gyan,

I guess you’ve joined this discussion late. It might be a good idea to review 
the LSR mailing list archives.

From: Gyan Mishra mailto:hayabusa...@gmail.com>>
Date: Thursday, May 21, 2020 at 1:51 PM
To: Huaimo Chen mailto:huaimo.c...@futurewei.com>>
Cc: Acee Lindem mailto:a...@cisco.com>>, 
"lsr@ietf.org<mailto:lsr@ietf.org>" mailto:lsr@ietf.org>>
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



On Thu, May 21, 2020 at 11:01 AM Huaimo Chen 
mailto:huaimo.c...@futurewei.com>> wrote:
Hi Gyan,

Thanks much for your questions.

 Gyan> How does this draft compare to the WG LC draft for flood reduction.  
Would they be two eventual standard options in the operators toolbox  or 
competing features for optimized flood reduction. Would having two flood 
reduction features standardized versus one default IGP flood reduction feature 
be confusing for operators.  Just as it was confusing to me.
https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=TGrkecn6m9liviazX7qqPglGqYEWu5Ekg2FRIaDpBZ8%3D=0>

[HC]: This draft plus the draft for flooding reduction can provide two 
modes of flooding reductions (i.e., centralized mode and distributed mode). The 
latter describes the two modes, but does not include any flooding topology 
computation algorithm for the distributed mode. The former proposes a flooding 
topology computation algorithm to be used in the distributed mode.

   Gyan> It maybe a good idea for both documents to reference each other as to 
how they play together or  in some respects if any provide a homogeneous 
complete holistic solution for flooding problem being solved.

It is a good idea to have this new draft reference the dynamic-flooding but not 
vice-versa. The existing dynamic flooding draft provides a framework for any 
dynamic flooding algorithm that provides a separate flooding topology. This 
algorithm is just the first to be formally proposed in a draft. Note that 
another algorithm was presented during the LSR virtual interim which replaced 
IETF 107.

In my opinion it may not be a bad idea even to combine both drafts so the 
solution is complete and holistic.  This will also make the overall 
specification flow nicely.

No – we’re not going to do this.

Thanks,
Acee

I know that efforts were made by LSR to have a common IGP solution, however 
there are many inherent differences between ISIS and OSPF that from IGP Link 
state protocol perspective you can treat like apples to apples but really it’s 
apples and oranges.  Maybe it might we wise to have separate draft for both and 
have references linking together as the same algorithm concept and 
mathematically however the actual code implementation would vary as the LSDB 
link state data structures are completely different.

Later = Dynamic flooding = 2 modes Centralized leader based and distributed

https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/

This later draft per section excerpt provides both centralized and distributed 
algorithm see below


6.4<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-dynamic-flooding-05#section-6.4>.
  Area Leader Responsibilities



   

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Yes and I have started reviewing the LSR mail archives as I am late in the
discussion for this.

If you have link to any particular dates in the archives would be helpful.

That sums up all the questions I have so if all answered in the archives
then I am all set.

I support the draft moving forward as flood reduction is a much needed
feature.

I think overall both drafts will really help large data centers with any
overlay underlay vxlan spine leaf meshed CLOS highly meshed topology that
scales out horizontally with a large spine footprint - this is a much much
needed feature.  This also helps eliminate complexity of the workaround of
using BGP in the underlay which to me adds tremendous complexity.

Kind regards

Gyan

On Thu, May 21, 2020 at 4:07 PM Acee Lindem (acee)  wrote:

> Speaking as WG Co-chair:
>
>
>
> Hi Gyan,
>
>
>
> I guess you’ve joined this discussion late. It might be a good idea to
> review the LSR mailing list archives.
>
>
>
> *From: *Gyan Mishra 
> *Date: *Thursday, May 21, 2020 at 1:51 PM
> *To: *Huaimo Chen 
> *Cc: *Acee Lindem , "lsr@ietf.org" 
> *Subject: *Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
>
>
>
>
> On Thu, May 21, 2020 at 11:01 AM Huaimo Chen 
> wrote:
>
> Hi Gyan,
>
>
>
> Thanks much for your questions.
>
>
>
>  Gyan> How does this draft compare to the WG LC draft for flood
> reduction.  Would they be two eventual standard options in the operators
> toolbox  or competing features for optimized flood reduction. Would having
> two flood reduction features standardized versus one default IGP flood
> reduction feature be confusing for operators.  Just as it was confusing to
> me.
>
> https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=TGrkecn6m9liviazX7qqPglGqYEWu5Ekg2FRIaDpBZ8%3D=0>
>
>
>
> [HC]: This draft plus the draft for flooding reduction can provide two
> modes of flooding reductions (i.e., centralized mode and distributed mode).
> The latter describes the two modes, but does not include any flooding
> topology computation algorithm for the distributed mode. The former
> proposes a flooding topology computation algorithm to be used in the
> distributed mode.
>
>
>
>Gyan> It maybe a good idea for both documents to reference each other
> as to how they play together or  in some respects if any provide a
> homogeneous complete holistic solution for flooding problem being solved.
>
>
>
> It is a good idea to have this new draft reference the dynamic-flooding
> but not vice-versa. The existing dynamic flooding draft provides a
> framework for any dynamic flooding algorithm that provides a separate
> flooding topology. This algorithm is just the first to be formally proposed
> in a draft. Note that another algorithm was presented during the LSR
> virtual interim which replaced IETF 107.
>
>
>
> In my opinion it may not be a bad idea even to combine both drafts so the
> solution is complete and holistic.  This will also make the overall
> specification flow nicely.
>
>
>
> No – we’re not going to do this.
>
>
>
> Thanks,
>
> Acee
>
>
>
> I know that efforts were made by LSR to have a common IGP solution,
> however there are many inherent differences between ISIS and OSPF that from
> IGP Link state protocol perspective you can treat like apples to apples but
> really it’s apples and oranges.  Maybe it might we wise to have separate
> draft for both and have references linking together as the same algorithm
> concept and mathematically however the actual code implementation would
> vary as the LSDB link state data structures are completely different.
>
>
>
> Later = Dynamic flooding = 2 modes Centralized leader based and
> distributed
>
>
>
> https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/
>
>
>
> This later draft per section excerpt provides both centralized and
> distributed algorithm see below
>
>
>
> *6.4 
> <https://datatracker.ietf.org/doc/html/draft-ietf-lsr-dynamic-flooding-05#section-6.4>.
>   Area Leader Responsibilities*
>
>
>
>If the Area Leader operates in centralized mode, it MUST advertise
>
>algorithm 0 in its Area Leader Sub-TLV.  In order for Dynamic
>
>Flooding to be enabled it also MUST compute and advertise a flooding
>
>topology for the area.  Th

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Acee Lindem (acee)]

Speaking as WG Co-chair:

Hi Gyan,

I guess you’ve joined this discussion late. It might be a good idea to review 
the LSR mailing list archives.

From: Gyan Mishra 
Date: Thursday, May 21, 2020 at 1:51 PM
To: Huaimo Chen 
Cc: Acee Lindem , "lsr@ietf.org" 
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



On Thu, May 21, 2020 at 11:01 AM Huaimo Chen 
mailto:huaimo.c...@futurewei.com>> wrote:
Hi Gyan,

Thanks much for your questions.

 Gyan> How does this draft compare to the WG LC draft for flood reduction.  
Would they be two eventual standard options in the operators toolbox  or 
competing features for optimized flood reduction. Would having two flood 
reduction features standardized versus one default IGP flood reduction feature 
be confusing for operators.  Just as it was confusing to me.
https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=TGrkecn6m9liviazX7qqPglGqYEWu5Ekg2FRIaDpBZ8%3D=0>

[HC]: This draft plus the draft for flooding reduction can provide two 
modes of flooding reductions (i.e., centralized mode and distributed mode). The 
latter describes the two modes, but does not include any flooding topology 
computation algorithm for the distributed mode. The former proposes a flooding 
topology computation algorithm to be used in the distributed mode.

   Gyan> It maybe a good idea for both documents to reference each other as to 
how they play together or  in some respects if any provide a homogeneous 
complete holistic solution for flooding problem being solved.

It is a good idea to have this new draft reference the dynamic-flooding but not 
vice-versa. The existing dynamic flooding draft provides a framework for any 
dynamic flooding algorithm that provides a separate flooding topology. This 
algorithm is just the first to be formally proposed in a draft. Note that 
another algorithm was presented during the LSR virtual interim which replaced 
IETF 107.

In my opinion it may not be a bad idea even to combine both drafts so the 
solution is complete and holistic.  This will also make the overall 
specification flow nicely.

No – we’re not going to do this.

Thanks,
Acee

I know that efforts were made by LSR to have a common IGP solution, however 
there are many inherent differences between ISIS and OSPF that from IGP Link 
state protocol perspective you can treat like apples to apples but really it’s 
apples and oranges.  Maybe it might we wise to have separate draft for both and 
have references linking together as the same algorithm concept and 
mathematically however the actual code implementation would vary as the LSDB 
link state data structures are completely different.

Later = Dynamic flooding = 2 modes Centralized leader based and distributed

https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/

This later draft per section excerpt provides both centralized and distributed 
algorithm see below


6.4<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-dynamic-flooding-05#section-6.4>.
  Area Leader Responsibilities



   If the Area Leader operates in centralized mode, it MUST advertise

   algorithm 0 in its Area Leader Sub-TLV.  In order for Dynamic

   Flooding to be enabled it also MUST compute and advertise a flooding

   topology for the area.  The Area Leader may update the flooding

   topology at any time, however, it should not destabilize the network

   with undue or overly frequent topology changes.  If the Area Leader

   operates in centralized mode and needs to advertise a new flooding

   topology, it floods the new flooding topology on both the new and old

   flooding topologies.



   If the Area Leader operates in distributed mode, it MUST advertise a

   non-zero algorithm in its Area Leader Sub-TLV.



   When the Area Leader advertises algorithm 0 in its Area Leader Sub-

   TLV and does not advertise a flooding topology, Dynamic Flooding is

   disabled for the area.  Note this applies whether the Area Leader

   intends to operate in centralized mode or in distributed mode.



   Note that once Dynamic Flooding is enabled, disabling it risks

   destabilizing the network.



6.5<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-dynamic-flooding-05#section-6.5>.
  Distributed Flooding Topology Calculation



   If the Area Leader advertises a non-zero algorithm in its Area Leader

   Sub-TLV, all nodes in the area that support Dynamic Flooding and the

   value of algorithm advertised by the Area Leader MUST compute the

   flooding topology based on the Area Leader's advertised algorithm.



   Nodes that do not support the value of algorith

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

n light of the flooding algorithm and seeing that at the bottom of section
6.5 mentions flooding algorithm are the IANA codepoints reserved for
flooding unique and non overlapping with the flex algo codepoints I believe
0-127.  I would think the flooding algorithm range of values is completely
separate since a different function then flex algo values.

https://datatracker.ietf.org/doc/html/draft-ietf-lsr-flex-algo-07


> Best Regards,
> Huaimo
> --
> *From:* Gyan Mishra 
> *Sent:* Thursday, May 21, 2020 10:36 AM
>
> *To:* Huaimo Chen 
> *Cc:* Acee Lindem (acee) ; lsr@ietf.org <
> lsr@ietf.org>
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
> On Wed, May 20, 2020 at 11:59 PM Huaimo Chen 
> wrote:
>
> Hi Gyan,
>
> Thanks much for your questions. My answers are inline below with [HC]..
>
> Best Regards,
> Huaimo
> ------
> *From:* Gyan Mishra 
> *Sent:* Wednesday, May 20, 2020 11:14 AM
> *To:* Huaimo Chen 
> *Cc:* Acee Lindem (acee) ; lsr@ietf.org <
> lsr@ietf.org>
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
> Huaimo
>
> This is a much needed feature that operators have been needing for densely
> meshed topologies that commonly exist in data centers to accommodate very
> high bandwidth E-W traffic.
> [HC]: Thank you very much.
>
> Below is link from Cisco which has introduced feature for dynamic flooding
> in clos high density ECMP data center topologies.
>
> Please look at the feature description and it does seem to be exactly the
> same as this draft.  Please confirm.
> [HC]: It seems different.
>
> There maybe other vendors due to industry demand have to get the feature
> deployed before it reaches standards vendor consensus with the IETF.
>
>
> https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.cisco.com%2Fc%2Fen%2Fus%2Fproducts%2Fcollateral%2Fswitches%2Fnexus-9000-series-switches%2Fwhite-paper-c11-743015.html=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=CPEu2451qkfD9440Ihj1bKPWl%2BzH%2BiuYUwuWpfzR%2B0Q%3D=0>
>
> We are testing this feature and planning to deploy but wanted to ensure
> that this is the same as the draft on the standards track.
> [HC]: The feature appears implemented draft "Dynamic Flooding on Dense
> Graphs", which does not include any flooding topology computation
> algorithm.
>
>
> Gyan> How does this draft compare to the WG LC draft for flood
> reduction.  Would they be two eventual standard options in the operators
> toolbox  or competing features for optimized flood reduction. Would having
> two flood reduction features standardized versus one default IGP flood
> reduction feature be confusing for operators.  Just as it was confusing to
> me.
>
>
> https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=TGrkecn6m9liviazX7qqPglGqYEWu5Ekg2FRIaDpBZ8%3D=0>
>
>
> Kind regards
>
> Gyan
>
>
> On Tue, May 19, 2020 at 11:52 PM Huaimo Chen 
> wrote:
>
> Hi Gyan,
>
> Thank you very much for your questions and support.
>
> This Flooding Topology Computation algorithm can be used in the Dynamic
> Flooding on Dense Graphs to compute the flooding topologies for the data
> center clos dense meshed topologies with many ECMP paths. It can be used by
> the area leader in the centralized mode to compute the flooding topology.
>
> Best Regards,
> Huaimo
> --
> *From:* Lsr  on behalf of Gyan Mishra <
> hayabusa...@gmail.com>
> *Sent:* Tuesday, May 19, 2020 2:39 AM
> *To:* Yanhe Fan 
> *Cc:* lsr@ietf.org ; Acee Lindem (acee)  40cisco@dmarc.ietf.org>
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
> I support WG adoption and have a few questions related to the draft.
>
> Does this flooding algorithm use the dynamic flooding algorithm used in
> data center clos dense meshed topologies with many ECMP paths where the
> flood is decoupled from the physical topology.  In the dynamic flooding
> algorith

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Gyan,

Thanks much for your questions.

 Gyan> How does this draft compare to the WG LC draft for flood reduction.  
Would they be two eventual standard options in the operators toolbox  or 
competing features for optimized flood reduction. Would having two flood 
reduction features standardized versus one default IGP flood reduction feature 
be confusing for operators.  Just as it was confusing to me.
https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=TGrkecn6m9liviazX7qqPglGqYEWu5Ekg2FRIaDpBZ8%3D=0>

[HC]: This draft plus the draft for flooding reduction can provide two 
modes of flooding reductions (i.e., centralized mode and distributed mode). The 
latter describes the two modes, but does not include any flooding topology 
computation algorithm for the distributed mode. The former proposes a flooding 
topology computation algorithm to be used in the distributed mode.

Best Regards,
Huaimo

From: Gyan Mishra 
Sent: Thursday, May 21, 2020 10:36 AM
To: Huaimo Chen 
Cc: Acee Lindem (acee) ; lsr@ietf.org 

Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



On Wed, May 20, 2020 at 11:59 PM Huaimo Chen 
mailto:huaimo.c...@futurewei.com>> wrote:
Hi Gyan,

Thanks much for your questions. My answers are inline below with [HC].

Best Regards,
Huaimo

From: Gyan Mishra mailto:hayabusa...@gmail.com>>
Sent: Wednesday, May 20, 2020 11:14 AM
To: Huaimo Chen mailto:huaimo.c...@futurewei.com>>
Cc: Acee Lindem (acee) 
mailto:40cisco@dmarc.ietf.org>>; 
lsr@ietf.org<mailto:lsr@ietf.org> mailto:lsr@ietf.org>>
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

Huaimo

This is a much needed feature that operators have been needing for densely 
meshed topologies that commonly exist in data centers to accommodate very high 
bandwidth E-W traffic.
[HC]: Thank you very much.

Below is link from Cisco which has introduced feature for dynamic flooding in 
clos high density ECMP data center topologies.

Please look at the feature description and it does seem to be exactly the same 
as this draft.  Please confirm.
[HC]: It seems different.

There maybe other vendors due to industry demand have to get the feature 
deployed before it reaches standards vendor consensus with the IETF.

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.cisco.com%2Fc%2Fen%2Fus%2Fproducts%2Fcollateral%2Fswitches%2Fnexus-9000-series-switches%2Fwhite-paper-c11-743015.html=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=CPEu2451qkfD9440Ihj1bKPWl%2BzH%2BiuYUwuWpfzR%2B0Q%3D=0>

We are testing this feature and planning to deploy but wanted to ensure that 
this is the same as the draft on the standards track.
[HC]: The feature appears implemented draft "Dynamic Flooding on Dense Graphs", 
which does not include any flooding topology computation algorithm.

Gyan> How does this draft compare to the WG LC draft for flood reduction.  
Would they be two eventual standard options in the operators toolbox  or 
competing features for optimized flood reduction. Would having two flood 
reduction features standardized versus one default IGP flood reduction feature 
be confusing for operators.  Just as it was confusing to me.


https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C60df274544ba4b75447f08d7fd947201%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637256686327604003=TGrkecn6m9liviazX7qqPglGqYEWu5Ekg2FRIaDpBZ8%3D=0>

Kind regards

Gyan


On Tue, May 19, 2020 at 11:52 PM Huaimo Chen 
mailto:huaimo.c...@futurewei.com>> wrote:
Hi Gyan,

Thank you very much for your questions and support.

This Flooding Topology Computation algorithm can be used in the Dynamic 
Flooding on Dense Graphs to compute the flooding topologies for the data center 
clos dense meshed topologies with many ECMP paths. It can be used by the area 
leader in the centralized mode to compute the flooding topology.

Best Regards,
Huaimo

From: Lsr mailto:lsr-boun...@ietf.org>> on behalf of Gyan 
Mishra mailto:hayabusa...@gmail.com>>
Sent: Tuesday, May 19, 2020 2

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

On Wed, May 20, 2020 at 11:59 PM Huaimo Chen 
wrote:

> Hi Gyan,
>
> Thanks much for your questions. My answers are inline below with [HC]..
>
> Best Regards,
> Huaimo
> --
> *From:* Gyan Mishra 
> *Sent:* Wednesday, May 20, 2020 11:14 AM
> *To:* Huaimo Chen 
> *Cc:* Acee Lindem (acee) ; lsr@ietf.org <
> lsr@ietf.org>
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
> Huaimo
>
> This is a much needed feature that operators have been needing for densely
> meshed topologies that commonly exist in data centers to accommodate very
> high bandwidth E-W traffic.
> [HC]: Thank you very much.
>
> Below is link from Cisco which has introduced feature for dynamic flooding
> in clos high density ECMP data center topologies.
>
> Please look at the feature description and it does seem to be exactly the
> same as this draft.  Please confirm.
> [HC]: It seems different.
>
> There maybe other vendors due to industry demand have to get the feature
> deployed before it reaches standards vendor consensus with the IETF.
>
>
> https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.cisco.com%2Fc%2Fen%2Fus%2Fproducts%2Fcollateral%2Fswitches%2Fnexus-9000-series-switches%2Fwhite-paper-c11-743015.html=02%7C01%7Chuaimo.chen%40futurewei.com%7Caf6069f07e9c4b9b881508d7fcd08b26%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637255844949669307=9nLFlmBSFxBQayL0fCiq864Ylvzyksk3U0GmZPbhPts%3D=0>
>
> We are testing this feature and planning to deploy but wanted to ensure
> that this is the same as the draft on the standards track.
> [HC]: The feature appears implemented draft "Dynamic Flooding on Dense
> Graphs", which does not include any flooding topology computation
> algorithm.
>

Gyan> How does this draft compare to the WG LC draft for flood
reduction.  Would they be two eventual standard options in the operators
toolbox  or competing features for optimized flood reduction. Would having
two flood reduction features standardized versus one default IGP flood
reduction feature be confusing for operators.  Just as it was confusing to
me.


https://datatracker.ietf.org/doc/draft-ietf-lsr-dynamic-flooding/

>
> Kind regards
>
> Gyan
>
>
> On Tue, May 19, 2020 at 11:52 PM Huaimo Chen 
> wrote:
>
> Hi Gyan,
>
> Thank you very much for your questions and support.
>
> This Flooding Topology Computation algorithm can be used in the Dynamic
> Flooding on Dense Graphs to compute the flooding topologies for the data
> center clos dense meshed topologies with many ECMP paths. It can be used by
> the area leader in the centralized mode to compute the flooding topology.
>
> Best Regards,
> Huaimo
> ------
> *From:* Lsr  on behalf of Gyan Mishra <
> hayabusa...@gmail.com>
> *Sent:* Tuesday, May 19, 2020 2:39 AM
> *To:* Yanhe Fan 
> *Cc:* lsr@ietf.org ; Acee Lindem (acee)  40cisco@dmarc.ietf.org>
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
> I support WG adoption and have a few questions related to the draft.
>
> Does this flooding algorithm use the dynamic flooding algorithm used in
> data center clos dense meshed topologies with many ECMP paths where the
> flood is decoupled from the physical topology.  In the dynamic flooding
> algorithm mentioned in centralized mode the flooding is computed by the
> area leader and distributed to all nodes.  In distributed mode each mode
> the area leader determines the algorithm and then each node computes the
> flooding topology based on the algorithm.
>
> This dynamic algorithm for optimized flood reduction would reduce the
> amount of redundant flooding in highly densely meshed ospf or Isis
> topologies.  So this optimization of flooding would improving overall link
> state routing protocol convergence.
>
> Gyan
>
> On Mon, May 18, 2020 at 3:37 PM Yanhe Fan  wrote:
>
> Support it as a co-author.
>
>
>
> Thanks,
>
> Yanhe
>
>
>
> *From:* Lsr  *On Behalf Of *Acee Lindem (acee)
> *Sent:* Friday, May 15, 2020 3:40 PM
> *To:* lsr@ietf.org
> *Subject:* [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
> This begins a 3 week (due to holidays) WG adoption call for the “Flooding
> Topology Computation Algorithm” draft. Please issue your support or
> objection to this list by 11:59 PM, UTC on June 5th, 2020. Here is a U

Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Xufeng Liu]

Support as a co-author.
Thanks,
- Xufeng

On Fri, May 15, 2020 at 3:40 PM Acee Lindem (acee)  wrote:

> This begins a 3 week (due to holidays) WG adoption call for the “Flooding
> Topology Computation Algorithm” draft. Please issue your support or
> objection to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL
> for your convenience.
>
>
>
> https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/
>
>
>
> Thanks,
> Acee
> ___
> Lsr mailing list
> Lsr@ietf.org
> https://www.ietf.org/mailman/listinfo/lsr
>
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Gyan,

Thanks much for your questions. My answers are inline below with [HC].

Best Regards,
Huaimo

From: Gyan Mishra 
Sent: Wednesday, May 20, 2020 11:14 AM
To: Huaimo Chen 
Cc: Acee Lindem (acee) ; lsr@ietf.org 

Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

Huaimo

This is a much needed feature that operators have been needing for densely 
meshed topologies that commonly exist in data centers to accommodate very high 
bandwidth E-W traffic.
[HC]: Thank you very much.

Below is link from Cisco which has introduced feature for dynamic flooding in 
clos high density ECMP data center topologies.

Please look at the feature description and it does seem to be exactly the same 
as this draft.  Please confirm.
[HC]: It seems different.

There maybe other vendors due to industry demand have to get the feature 
deployed before it reaches standards vendor consensus with the IETF.

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.cisco.com%2Fc%2Fen%2Fus%2Fproducts%2Fcollateral%2Fswitches%2Fnexus-9000-series-switches%2Fwhite-paper-c11-743015.html=02%7C01%7Chuaimo.chen%40futurewei.com%7Caf6069f07e9c4b9b881508d7fcd08b26%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637255844949669307=9nLFlmBSFxBQayL0fCiq864Ylvzyksk3U0GmZPbhPts%3D=0>

We are testing this feature and planning to deploy but wanted to ensure that 
this is the same as the draft on the standards track.
[HC]: The feature appears implemented draft "Dynamic Flooding on Dense Graphs", 
which does not include any flooding topology computation algorithm.

Kind regards

Gyan


On Tue, May 19, 2020 at 11:52 PM Huaimo Chen 
mailto:huaimo.c...@futurewei.com>> wrote:
Hi Gyan,

Thank you very much for your questions and support.

This Flooding Topology Computation algorithm can be used in the Dynamic 
Flooding on Dense Graphs to compute the flooding topologies for the data center 
clos dense meshed topologies with many ECMP paths. It can be used by the area 
leader in the centralized mode to compute the flooding topology.

Best Regards,
Huaimo

From: Lsr mailto:lsr-boun...@ietf.org>> on behalf of Gyan 
Mishra mailto:hayabusa...@gmail.com>>
Sent: Tuesday, May 19, 2020 2:39 AM
To: Yanhe Fan mailto:y...@casa-systems.com>>
Cc: lsr@ietf.org<mailto:lsr@ietf.org> mailto:lsr@ietf.org>>; Acee 
Lindem (acee) 
mailto:40cisco@dmarc.ietf.org>>
Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


I support WG adoption and have a few questions related to the draft.

Does this flooding algorithm use the dynamic flooding algorithm used in data 
center clos dense meshed topologies with many ECMP paths where the flood is 
decoupled from the physical topology.  In the dynamic flooding algorithm 
mentioned in centralized mode the flooding is computed by the area leader and 
distributed to all nodes.  In distributed mode each mode the area leader 
determines the algorithm and then each node computes the flooding topology 
based on the algorithm.

This dynamic algorithm for optimized flood reduction would reduce the amount of 
redundant flooding in highly densely meshed ospf or Isis topologies.  So this 
optimization of flooding would improving overall link state routing protocol 
convergence.

Gyan

On Mon, May 18, 2020 at 3:37 PM Yanhe Fan 
mailto:y...@casa-systems.com>> wrote:

Support it as a co-author.



Thanks,

Yanhe



From: Lsr mailto:lsr-boun...@ietf.org>> On Behalf Of Acee 
Lindem (acee)
Sent: Friday, May 15, 2020 3:40 PM
To: lsr@ietf.org<mailto:lsr@ietf.org>
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7Caf6069f07e9c4b9b881508d7fcd08b26%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637255844949679298=08cwC5X8u06cotUPxaWyOq3euYKGK9Pfh0pieb7Tqf0%3D=0>



Thanks,
Acee

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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[tony . li]

Hi Gyan,


> This is a much needed feature that operators have been needing for densely 
> meshed topologies that commonly exist in data centers to accommodate very 
> high bandwidth E-W traffic.

Thank you.

> Please look at the feature description and it does seem to be exactly the 
> same as this draft.  Please confirm. 


It would appear to be a different, proprietary, and unpublished algorithm.  

This will give us three different implementations, using three different 
algorithms, none of which will inter-operate.  Whee!!! :-(


> There maybe other vendors due to industry demand have to get the feature 
> deployed before it reaches standards vendor consensus with the IETF.


Our implementation shipped last year.


> We are testing this feature and planning to deploy but wanted to ensure that 
> this is the same as the draft on the standards track.


It does not appear to be, but someone from Cisco should confirm.

Tony

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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

Huaimo

This is a much needed feature that operators have been needing for densely
meshed topologies that commonly exist in data centers to accommodate very
high bandwidth E-W traffic.

Below is link from Cisco which has introduced feature for dynamic flooding
in clos high density ECMP data center topologies.

Please look at the feature description and it does seem to be exactly the
same as this draft.  Please confirm.

There maybe other vendors due to industry demand have to get the feature
deployed before it reaches standards vendor consensus with the IETF.


https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-743015.html

We are testing this feature and planning to deploy but wanted to ensure
that this is the same as the draft on the standards track.

Kind regards

Gyan


On Tue, May 19, 2020 at 11:52 PM Huaimo Chen 
wrote:

> Hi Gyan,
>
> Thank you very much for your questions and support.
>
> This Flooding Topology Computation algorithm can be used in the Dynamic
> Flooding on Dense Graphs to compute the flooding topologies for the data
> center clos dense meshed topologies with many ECMP paths. It can be used by
> the area leader in the centralized mode to compute the flooding topology.
>
> Best Regards,
> Huaimo
> --
> *From:* Lsr  on behalf of Gyan Mishra <
> hayabusa...@gmail.com>
> *Sent:* Tuesday, May 19, 2020 2:39 AM
> *To:* Yanhe Fan 
> *Cc:* lsr@ietf.org ; Acee Lindem (acee)  40cisco@dmarc.ietf.org>
> *Subject:* Re: [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
> I support WG adoption and have a few questions related to the draft.
>
> Does this flooding algorithm use the dynamic flooding algorithm used in
> data center clos dense meshed topologies with many ECMP paths where the
> flood is decoupled from the physical topology.  In the dynamic flooding
> algorithm mentioned in centralized mode the flooding is computed by the
> area leader and distributed to all nodes.  In distributed mode each mode
> the area leader determines the algorithm and then each node computes the
> flooding topology based on the algorithm.
>
> This dynamic algorithm for optimized flood reduction would reduce the
> amount of redundant flooding in highly densely meshed ospf or Isis
> topologies.  So this optimization of flooding would improving overall link
> state routing protocol convergence.
>
> Gyan
>
> On Mon, May 18, 2020 at 3:37 PM Yanhe Fan  wrote:
>
> Support it as a co-author.
>
>
>
> Thanks,
>
> Yanhe
>
>
>
> *From:* Lsr  *On Behalf Of *Acee Lindem (acee)
> *Sent:* Friday, May 15, 2020 3:40 PM
> *To:* lsr@ietf.org
> *Subject:* [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
> This begins a 3 week (due to holidays) WG adoption call for the “Flooding
> Topology Computation Algorithm” draft. Please issue your support or
> objection to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL
> for your convenience.
>
>
>
> https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C67789a4ab2b84b08385508d7fbbf82c1%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637254672267311232=yBEjECqdVgodmO5T3C%2FRQE21bFKOWX6lpJA0CMdJ18A%3D=0>
>
>
>
> Thanks,
> Acee
> ___
> Lsr mailing list
> Lsr@ietf.org
> https://www.ietf.org/mailman/listinfo/lsr
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ietf.org%2Fmailman%2Flistinfo%2Flsr=02%7C01%7Chuaimo.chen%40futurewei.com%7C67789a4ab2b84b08385508d7fbbf82c1%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637254672267311232=hTQLnO1j3UqxcJP2hEs9DpYQiSOZpw00SF2LNrwgtKc%3D=0>
>
> --
>
>
> <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C67789a4ab2b84b08385508d7fbbf82c1%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637254672267321230=mYvXS9UFr523Pxr9%2B3Il52dsAEPsTWglyYsCtUDUdo0%3D=0>
>
> <https://www.google.com/maps/search/13101+Columbia+Pike+%0D%0A+Silver+Spring,+MD?entry=gmail=g>
>
> *Gyan Mishra*
>
> *Network Solutions A**rchitect *
>
>
>
> *M 301 502-1347 13101 Columbia Pike
> <https://www.google.com/maps/search/13101+Columbia+Pike+%0D%0A+Silver+Spring,+MD?entry=gmail=g>
> *Silver Spring, MD
> <https://www.google.com/maps/search/13101+Columbia+Pike+%0D%0A+Silver+Spring,+MD?entry=gmail=g>
>
> --

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[LEI LIU]

Support it as a co-author.



Thanks,

Best regards,


Lei

On Fri, May 15, 2020 at 12:40 PM Acee Lindem (acee)  wrote:

> This begins a 3 week (due to holidays) WG adoption call for the “Flooding
> Topology Computation Algorithm” draft. Please issue your support or
> objection to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL
> for your convenience.
>
>
>
> https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/
>
>
>
> Thanks,
> Acee
> ___
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Hi Gyan,

Thank you very much for your questions and support.

This Flooding Topology Computation algorithm can be used in the Dynamic 
Flooding on Dense Graphs to compute the flooding topologies for the data center 
clos dense meshed topologies with many ECMP paths. It can be used by the area 
leader in the centralized mode to compute the flooding topology.

Best Regards,
Huaimo

From: Lsr  on behalf of Gyan Mishra 

Sent: Tuesday, May 19, 2020 2:39 AM
To: Yanhe Fan 
Cc: lsr@ietf.org ; Acee Lindem (acee) 

Subject: Re: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


I support WG adoption and have a few questions related to the draft.

Does this flooding algorithm use the dynamic flooding algorithm used in data 
center clos dense meshed topologies with many ECMP paths where the flood is 
decoupled from the physical topology.  In the dynamic flooding algorithm 
mentioned in centralized mode the flooding is computed by the area leader and 
distributed to all nodes.  In distributed mode each mode the area leader 
determines the algorithm and then each node computes the flooding topology 
based on the algorithm.

This dynamic algorithm for optimized flood reduction would reduce the amount of 
redundant flooding in highly densely meshed ospf or Isis topologies.  So this 
optimization of flooding would improving overall link state routing protocol 
convergence.

Gyan

On Mon, May 18, 2020 at 3:37 PM Yanhe Fan 
mailto:y...@casa-systems.com>> wrote:

Support it as a co-author.



Thanks,

Yanhe



From: Lsr mailto:lsr-boun...@ietf.org>> On Behalf Of Acee 
Lindem (acee)
Sent: Friday, May 15, 2020 3:40 PM
To: lsr@ietf.org<mailto:lsr@ietf.org>
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call



This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf..org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F=02%7C01%7Chuaimo.chen%40futurewei.com%7C67789a4ab2b84b08385508d7fbbf82c1%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637254672267311232=yBEjECqdVgodmO5T3C%2FRQE21bFKOWX6lpJA0CMdJ18A%3D=0>



Thanks,
Acee

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Gyan Mishra

Network Solutions Architect

M 301 502-1347
13101 Columbia Pike
Silver Spring, MD

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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Linda Dunbar]

Support the WG Adoption.

Linda Dunbar

From: Lsr mailto:lsr-boun...@ietf.org>> On Behalf Of Acee 
Lindem (acee)
Sent: Friday, May 15, 2020 3:40 PM
To: lsr@ietf.org
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Gyan Mishra]

I support WG adoption and have a few questions related to the draft.

Does this flooding algorithm use the dynamic flooding algorithm used in
data center clos dense meshed topologies with many ECMP paths where the
flood is decoupled from the physical topology.  In the dynamic flooding
algorithm mentioned in centralized mode the flooding is computed by the
area leader and distributed to all nodes.  In distributed mode each mode
the area leader determines the algorithm and then each node computes the
flooding topology based on the algorithm.

This dynamic algorithm for optimized flood reduction would reduce the
amount of redundant flooding in highly densely meshed ospf or Isis
topologies.  So this optimization of flooding would improving overall link
state routing protocol convergence.

Gyan

On Mon, May 18, 2020 at 3:37 PM Yanhe Fan  wrote:

> Support it as a co-author.
>
>
>
> Thanks,
>
> Yanhe
>
>
>
> *From:* Lsr  *On Behalf Of *Acee Lindem (acee)
> *Sent:* Friday, May 15, 2020 3:40 PM
> *To:* lsr@ietf.org
> *Subject:* [Lsr] Flooding Topology Computation Algorithm -
> draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call
>
>
>
> This begins a 3 week (due to holidays) WG adoption call for the “Flooding
> Topology Computation Algorithm” draft. Please issue your support or
> objection to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL
> for your convenience.
>
>
>
> https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/
>
>
>
> Thanks,
> Acee
> ___
> Lsr mailing list
> Lsr@ietf.org
> https://www.ietf.org/mailman/listinfo/lsr
>
-- 



*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Yanhe Fan]

Support it as a co-author.

Thanks,
Yanhe

From: Lsr  On Behalf Of Acee Lindem (acee)
Sent: Friday, May 15, 2020 3:40 PM
To: lsr@ietf.org
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Qin Wu]

Support this work.

-Qin
发件人: lsr-boun...@ietf.org 
[mailto:lsr-boun...@ietf.org] 代表 Acee Lindem (acee)
发送时间: 2020年5月16日 3:40
收件人: lsr@ietf.org
主题: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.

https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/

Thanks,
Acee
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Re: [Lsr] Flooding Topology Computation Algorithm - draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call

[Huaimo Chen]

Support.

Best Regards,
Huaimo as co-author

From: Lsr  on behalf of Acee Lindem (acee) 

Sent: Friday, May 15, 2020 3:39 PM
To: lsr@ietf.org 
Subject: [Lsr] Flooding Topology Computation Algorithm - 
draft-cc-lsr-flooding-reduction-08 Working Group Adoption Call


This begins a 3 week (due to holidays) WG adoption call for the “Flooding 
Topology Computation Algorithm” draft. Please issue your support or objection 
to this list by 11:59 PM, UTC on June 5th, 2020. Here is a URL for your 
convenience.



https://datatracker.ietf.org/doc/draft-cc-lsr-flooding-reduction/



Thanks,
Acee
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