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

[Huaimo Chen <[e-mail]>]

Hi Peter,

    My explanations/answers are in line below with prefix [HC].

-----Original Message-----
From: Peter Psenak [mailto:[e-mail]] 
Sent: Wednesday, February 6, 2019 4:58 AM
To: Huaimo Chen <[e-mail]>; Acee Lindem (acee) <[e-mail]>; Christian Hopps <[e-mail]>; [e-mail]
Subject: Re: [Lsr] Moving Forward [Re: Flooding Reduction Draft Redux]

Hi Huaimo,

On 03/02/2019 17:58 , Huaimo Chen wrote:
> Hi Acee,
>
>
>
>     I agree with you on keeping the signaling for two modes. The other 
> parts for the distributed solution need to be removed.

There are no "other" parts specific for the distributed solution.

[HC] Some behaviors for the distributed solution/mode are described in draft-li-dynamic-flooding. For example, there are a few of places from page 27 to 30, which define the behaviors specific for the distributed solution/mode.

draft-li-dyanmic-flooding defines:

1. the signalling that is common and used by both modes 2. distribution of the flooding-topology, which is specific to centralized mode 3. common behavior of the nodes that support the extension, which is independent of the mode of operation.

[HC] In addition to these, draft-cc-lsr-flooding-reduction defines more, including concrete protections, operations, and algorithms for computing a flooding topology.

Best Regards,
Huaimo

thanks,
Peter


>
>
>
> Best Regards,
>
> Huaimo
>
> *From:* Acee Lindem (acee) [mailto:[e-mail]]
> *Sent:* Sunday, February 3, 2019 11:45 AM
> *To:* Huaimo Chen <[e-mail]>; Christian Hopps 
> <[e-mail]>; [e-mail]
> *Subject:* Re: [Lsr] Moving Forward [Re: Flooding Reduction Draft 
> Redux]
>
>
>
> Hi Huaimo,
>
>
>
> See inline.
>
>
>
> *From: *Lsr <[e-mail] <mailto:[e-mail]>> on 
> behalf of Huaimo Chen <[e-mail] 
> <mailto:[e-mail]>>
> *Date: *Saturday, February 2, 2019 at 12:27 AM
> *To: *Christian Hopps <[e-mail] <mailto:[e-mail]>>, 
> "[e-mail] <mailto:[e-mail]>" <[e-mail] 
> <mailto:[e-mail]>>
> *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?
>
>
>
> Thanks,
>
> Acee
>
>
>
> Best Regards,
>
> Huaimo
>
>
>
> -----Original Message-----
>
> From: Lsr [mailto:[e-mail]] On Behalf Of Christian Hopps
>
> Sent: Friday, February 1, 2019 7:26 AM
>
> To: [e-mail] <mailto:[e-mail]>
>
> Cc: [e-mail] <mailto:[e-mail]>
>
> 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 algorithm.
>
>
>
> - 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 algorithm
>
>    (draft-cc-ospf-flooding-reduction)
>
>
>
> - 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 standardization.
>
>
>
> Does anyone see a serious problem with this path forward?
>
>
>
> Thanks,
>
> Chris & Acee.
>
> LSR Chairs.
>
>
>
> Christian Hopps <[e-mail] <mailto:[e-mail]>> 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_HaBNdfP
> bgxGIp22cnaWS
>
>>   - 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)
>
>>   - *SMALL CHANGE TO SUPPORT DISTRIBUTED ALGORITHM*.
>
>>   - 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)
>
>>   - *LARGE CHANGE ADDS NEW CENTRALIZED SOLUTION*.
>
>>
>
>> - 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)
>
>
>
>
>
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