Hi Acee,

    I agree with you on keeping the signaling for two modes. The other parts 
for the distributed solution need to be removed.

Best Regards,
From: Acee Lindem (acee) [mailto:a...@cisco.com]
Sent: Sunday, February 3, 2019 11:45 AM
To: Huaimo Chen <huaimo.c...@huawei.com>; Christian Hopps <cho...@chopps.org>; 
Subject: Re: [Lsr] Moving Forward [Re: Flooding Reduction Draft Redux]

Hi Huaimo,

See inline.

From: Lsr <lsr-boun...@ietf.org<mailto:lsr-boun...@ietf.org>> on behalf of 
Huaimo Chen <huaimo.c...@huawei.com<mailto:huaimo.c...@huawei.com>>
Date: Saturday, February 2, 2019 at 12:27 AM
To: Christian Hopps <cho...@chopps.org<mailto:cho...@chopps.org>>, 
"lsr@ietf.org<mailto:lsr@ietf.org>" <lsr@ietf.org<mailto:lsr@ietf.org>>
Subject: Re: [Lsr] Moving Forward [Re: Flooding Reduction Draft Redux]

Hi Everyone,

We proposed the distributed solution first, and Tony proposed the centralized 
solution first. Tony added the distributed solution (except for the algorithms 
to compute flooding topology) into his draft. And then we added the centralized 
solution into our draft. The latest versions of the two drafts have largely 
converged at least at the high level to a solution for solving the same problem.

Our draft has multiple key technical advantages over Tony’s draft as we 
described in our email to the LSR list, which are summarized below:

1.       It uses a fraction of flooding resource (i.e., it is multiple times 
more efficient in flooding topology encoding);

2.       It provides fault tolerance to multiple failures, minimizing impact on 
network convergence, thus minimizing traffic lose; and

3.       It is simpler and needs less processing time (i.e., faster and more 
efficient) in multiple scenarios.

Based on the technical merits, our draft should be moved forward. However, 
Chair proposed to move Tony’s draft forward and have us work on a distributed 
algorithm as we started with.

I think that the distributed solution in Tony’s draft needs to be removed and 
they work on the centralized solution. We remove the centralized solution from 
our draft and work on the distributed solution.

I’m against “cutting the baby in half” given that the signaling for the 
distributed solution is a proper subset of what is required for the centralized 
solution. It is undesirable to have different signaling for the two modes. For 
the distributed algorithm you are proposing, do see problems with the signaling?



Best Regards,


-----Original Message-----

From: Lsr [mailto:lsr-boun...@ietf.org] On Behalf Of Christian Hopps

Sent: Friday, February 1, 2019 7:26 AM

To: lsr@ietf.org<mailto:lsr@ietf.org>

Cc: cho...@chopps.org<mailto:cho...@chopps.org>

Subject: [Lsr] Moving Forward [Re: Flooding Reduction Draft Redux]

Summary of where we are at with dynamic flooding reduction:

- We have a well written original work that came first and described the 
problems as well as a TLVs to allow for a centralized solution 
(draft-li-dyanmic-flooding). We do not need to standardize the centralized 

- A small change to this work allowed for distributed algorithms and for 
outside work on distributed algorithms to continue in parallel.

- We have another original work that started primarily as a distributed 


- Finally we also have:

   - Cross-pollination of ideas.

   - Failed attempts at merging.

   - An authors list "Arms-Race".

Moving forward:

- During IETF 103 I proposed we have no conflict if we:

   1) adopt draft-li-lsr-dyanmic-flooding as the base WG document.

   2) have authors of draft-cc-lsr-flooding-reduction work on a distributed 
algorithm as they started with.

- Acee agreed during the meeting (as chair) that this was the best way forward. 
We had some agreement form the floor as well..

- Any good ideas regarding the distribution of a centralized topology can be 
debated and added (with appropriate attribution) to the base document after we 
adopt one.

- This is what happens when we adopt a document as WG work, we work on it.

- The original authors of the distributed solution can continue to work on 
their distributed algorithm in a separate document which would also need 

Does anyone see a serious problem with this path forward?


Chris & Acee.

LSR Chairs.

Christian Hopps <cho...@chopps.org<mailto:cho...@chopps.org>> writes:

> We've had the authors of the individual conflicting drafts take a shot at 
> merging their work.


>    This has failed.


> Here is the full history (which I also summarized during IETF103 as well). I 
> will send a second email discussing this.


> - Jan 2, 2018 Publication: draft-li-dynamic-flooding and 
> drfat-li-dynamic-flooding-isis

>   published centralized solution.


> - Mar 5, 2018 Publication: draft-cc-isis-flooding-reduction and 
> draft-cc-ospf-flooding-reduction

>   published distributed solution.

>   - mention of centralized solution asserting it is not good choice.


> - IETF 101 (Mar 2018)

>   - Video: 
> https://www.youtube.com/watch?v=qHmT4ytMn4w&list=PLC86T-6ZTP5j_HaBNdfPbgxGIp22cnaWS

>   - Minutes: 
> https://datatracker.ietf.org/meeting/101/materials/minutes-101-lsr-00

>   - draft-li-dynamic-flooding-02 presented (1 author). at IETF 101

>     - Generally well received.

>   - draft-cc-ospf-flooding-reduction-00 (4 authors) presented.

>     - Serious problems immediately found during presentation -- not fully 
> baked.


> - Mar 18, 2018 draft-li-dynamic-flooding-03 published (1 author)

> - Mar 27, 2018 draft-li-dynamic-flooding-04 published (1 author)

> - Apr 20, 2018 draft-cc-ospf-flooding-reduction-01 revised

> - Jun 28, 2018 draft-li-dynamic-flooding-05 published (2 authors)


>   - Does not specify distributed algorithm only how to indicate one in use, 
> small change.


> - Jul 2, 2018 draft-cc-ospf-flooding-reduction-02 published


> - IETF 102 (Jul 14, 2018)

>   - draft-li-dynamic-flooding-05 presented.

>   - draft-cc-ospf-flooding-reduction-02 presented.


> - Sep 12, 2018 draft-cc-ospf-flooding-reduction-03 (4 authors)



> - Sep 20, 2018 draft-cc-ospf-flooding-reduction-04 (4 authors)


> - Oct 21, 2018 draft-li-lsr-dynamic-flooding-00 and -01 (5 authors)


> - IETF 103 (Nov 3, 2018)


>   - Chairs give direction


>     - draft-li-lsr-dynamic-flooding-05 having come first, being well written 
> and not

>       specifying a distributed algorithm (merely allowing for one) is the 
> correct vehicle

>       to adopt as a base document.


>     - Distributed algorithm work (the original basis for 
> draft-cc-ospf-flooding-reduction)

>       should continue as a separate document form the base which would thus 
> we have no

>       conflicts.


> - In the meantime the authors try and merge work, this fails.


> - Dec 3, 2018 draft-li-lsr-dynamic-flooding-02 (7 authors)


> - Dec 10, 2018 draft-cc-lsr-flooding-reduction-00 (4 authors)


> - Jan 7, 2019  draft-cc-lsr-flooding-reduction-01 (8 authors)

Lsr mailing list

Reply via email to