Hi Huaimo Thank you for answering my questions.
Replies in-line On Sun, May 24, 2020 at 10:25 PM Huaimo Chen <huaimo.c...@futurewei.com> wrote: > Hi Gyan, > > Thanks much for your comments and suggestions. My answers/explanations > are inline below. > > Best Regards, > Huaimo > ------------------------------ > *From:* Gyan Mishra <hayabusa...@gmail.com> > *Sent:* Friday, May 22, 2020 9:11 PM > *To:* Huaimo Chen <huaimo.c...@futurewei.com> > *Cc:* Acee Lindem (acee) <a...@cisco.com>; lsr@ietf.org <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 <hayabusa...@gmail.com> 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 <huaimo.c...@futurewei.com> > wrote: > > Hi Gyan, > > Thanks much for your questions. My answers/explanations are inline > below. > > Best Regards, > Huaimo > ------------------------------ > *From:* Gyan Mishra <hayabusa...@gmail.com> > *Sent:* Thursday, May 21, 2020 10:13 PM > *To:* Acee Lindem (acee) <a...@cisco.com> > *Cc:* Huaimo Chen <huaimo.c...@futurewei.com>; lsr@ietf.org <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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931306983861&sdata=IFYiJFuxf4UAMRmjxDf%2BTICOWslqJxCWjWwYYJM%2F6uQ%3D&reserved=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%2F%2Fwww.ietf.org%2Fid%2Fdraft-chen-lsr-dynamic-flooding-algorithm-00.html&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931306988838&sdata=DlhahSNtm%2Ft406GcNtbGGq7uhFKfAqHO72Cm0vQdIo8%3D&reserved=0> > > 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) <a...@cisco.com> wrote: > > Hi Gyan, > > > > *From: *Gyan Mishra <hayabusa...@gmail.com> > *Date: *Thursday, May 21, 2020 at 4:20 PM > *To: *Acee Lindem <a...@cisco.com> > *Cc: *Huaimo Chen <huaimo.c...@futurewei.com>, "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/ > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-chen-lsr-dynamic-flooding-algorithm%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931306993818&sdata=f93gTdRXOpDko4jB0G%2B1Ixebs%2FrDHfmJ7WCWExPD5EI%3D&reserved=0> > > > > You can see they both make use of the dynamic flooding infra in > 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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931306998798&sdata=y7jC5eotw%2BebdD4dDfvO7pSlh8JUYurUyAC4kFJDpfY%3D&reserved=0> > > > > Thanks, > > Acee > > > > > > > > > > Kind regards > > > > Gyan > > > > On Thu, May 21, 2020 at 4:07 PM Acee Lindem (acee) <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 <hayabusa...@gmail.com> > *Date: *Thursday, May 21, 2020 at 1:51 PM > *To: *Huaimo Chen <huaimo.c...@futurewei.com> > *Cc: *Acee Lindem <a...@cisco.com>, "lsr@ietf.org" <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 <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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931306998798&sdata=y7jC5eotw%2BebdD4dDfvO7pSlh8JUYurUyAC4kFJDpfY%3D&reserved=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/ > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-ietf-lsr-dynamic-flooding%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307003777&sdata=b5DAj1yMUCRnkNtCjslcw8%2BhFQvZDFS%2FQZ1j9eRX5ts%3D&reserved=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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307008751&sdata=jKC3VcXH%2Bo64b4sgsoce8QmETmJm4vLNdCucfrLyCAg%3D&reserved=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%23section-6.5&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307013733&sdata=1XXbBG%2Fo%2Ft6zGyxqPQdbMZQLET3%2FaxrKj516zl1Ayn8%3D&reserved=0>. > 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 algorithm advertised by the > > Area Leader MUST continue to use standard flooding mechanism as > > defined by the protocol. > > > > Nodes that do not support the value of algorithm advertised by the > > Area Leader MUST be considered as Dynamic Flooding incapable nodes by > > the Area Leader. > > > > If the value of the algorithm advertised by the Area Leader is from > > the range 128-254 (private distributed algorithms), it is the > responsibility of the > > network operator to guarantee that all nodes in the area have a common > understanding of what the given algorithm value represents. > > > > Former = WG LC > > 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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307018706&sdata=zf%2FK80oG8tz90g15eVrkGeyGc5fhBym5PJezCFfSi9A%3D&reserved=0> > > > > Provides algorithm for distributed mode for this draft as well as the > algorithm to be used for distributed mode later dynamic flooding draft > > > > Separate question- > > > > In 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 > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-ietf-lsr-flex-algo-07&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307023687&sdata=MkDKud9pIJUwwoN%2F7w71fnOXfwu38sk4qwkGmDspUKI%3D&reserved=0> > > > > > > Best Regards, > > Huaimo > ------------------------------ > > *From:* Gyan Mishra <hayabusa...@gmail.com> > *Sent:* Thursday, May 21, 2020 10:36 AM > > > *To:* Huaimo Chen <huaimo.c...@futurewei.com> > *Cc:* Acee Lindem (acee) <acee=40cisco....@dmarc.ietf.org>; 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 <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 <hayabusa...@gmail.com> > *Sent:* Wednesday, May 20, 2020 11:14 AM > *To:* Huaimo Chen <huaimo.c...@futurewei.com> > *Cc:* Acee Lindem (acee) <acee=40cisco....@dmarc.ietf.org>; 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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307028662&sdata=NM0O3bq44tQ5GxZWm08rVjOh34mJjI1QsQ8DKFMgrAI%3D&reserved=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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307033643&sdata=tk5GwzA0o%2Bheui0Hl3nIpNwmNXM0QW%2FEXRbDQav8y54%3D&reserved=0> > > > > Kind regards > > > > Gyan > > > > > > On Tue, May 19, 2020 at 11:52 PM Huaimo Chen <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 <lsr-boun...@ietf.org> on behalf of Gyan Mishra < > hayabusa...@gmail.com> > *Sent:* Tuesday, May 19, 2020 2:39 AM > *To:* Yanhe Fan <y...@casa-systems.com> > *Cc:* lsr@ietf.org <lsr@ietf.org>; Acee Lindem (acee) <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 <y...@casa-systems.com> wrote: > > Support it as a co-author. > > > > Thanks, > > Yanhe > > > > *From:* Lsr <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/ > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-cc-lsr-flooding-reduction%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307038619&sdata=Rg7ZsHHsYJnJS7SpYUCLRsrDZ86Gi0iyKD2vMcjbboM%3D&reserved=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&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307043598&sdata=JDfLRjkZ4PI%2BwVcV0Mm0LXqq4Pzl3wz7BWWpv0zTtq0%3D&reserved=0> > > -- > > *Error! Filename not specified.* > <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307048576&sdata=gHSFT4GR6ZWS2MoTOPOVT%2BtTnF3wtTfRi5r1u6nzmcI%3D&reserved=0> > > *Gyan > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307053548&sdata=5RCW%2FwKABspmTndYt2yddKU2cGmYRpylfBQrM44LVZ0%3D&reserved=0>Mishra* > > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307058534&sdata=6kQPY2lr7kCb1D8TK8FyEcLUhEw%2BXbGo5wq25P1%2BCN8%3D&reserved=0>*Network > Solutions Architect * > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307063514&sdata=KYMkolhI78NOupCfu2t4loUYoqPOz4DhWyVE5B6YefI%3D&reserved=0> > > > > *M 301 502-1347 > <https://www.google.com/maps/search/13101%0D%0A+Columbia+Pike+%0D%0A+Silver%0D%0A+Spring,+MD?entry=gmail&source=g>13101 > Columbia Pike > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307068486&sdata=efWfnCnZLIuib%2FkjHpXFoRTG%2FtueVoh5yTltBhLr4y4%3D&reserved=0> > *Silver Spring, MD > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307073469&sdata=DU1ttb6xRduWgtpsBD6WNSWjma%2BtmtQdS%2FfOkth%2FwYc%3D&reserved=0> > > > > -- > > *Error! Filename not specified.* > <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307078448&sdata=0Oy2TQby8nTywn4XD8Zlsf8pbX34m0xOcwFcPdDl6u0%3D&reserved=0> > > *Gyan Mishra* > > *Network Solutions Architect * > > > > *M 301 502-1347 > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307083424&sdata=DDxMBzfPAQ4XWIlzTfnZSp%2Fn5Q2Q1eAqZffx%2BHM4aig%3D&reserved=0>13101 > Columbia Pike > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307083424&sdata=KSSlepfFHvtyqtOAbwIAdqkXy9RF%2FdOfo7%2FDz5RHp7k%3D&reserved=0> > *Silver Spring, MD > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307088401&sdata=8N6QAF6sCbXNbIhQQDT%2B7LbdWxWK5PX5kcfqeSA8PW0%3D&reserved=0> > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307093381&sdata=gM%2FzFPLLYGGKVIywDfe1VLMFtva0uGeYVwqjk4as53g%3D&reserved=0> > > <https://www.google.com/maps/search/13101%0D%0A+Columbia+Pike+%0D%0A+Silver%0D%0A+Spring,+MD?entry=gmail&source=g> > > > > -- > > *Error! Filename not specified.* > <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307098359&sdata=RFI30Fh8pkVGzCIo0t%2FuhBIYcu6cFYMQnfAKH9TCXXM%3D&reserved=0> > > *Gyan Mishra* > > *Network Solutions Architect * > > > > *M 301 502-1347 13101 Columbia Pike > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307103340&sdata=JJvVXt2V%2B4qdM6D8hsCCltvguXzAGUPqzJAF2cSurVo%3D&reserved=0> > *Silver Spring, MD > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307108314&sdata=zZ9exHtpFs%2B7d%2BTLGDwewg8ogHEksDYKQ%2FlHoXfS5R4%3D&reserved=0> > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307113289&sdata=%2FvTes4sdQnRrA93lMZPAu%2BJeOuSZS%2BHN2NDIol5vkYU%3D&reserved=0> > > > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307118270&sdata=CClF2UDqnAIwJ%2FfohMZudsssA%2FOMvzcgQfNPGQaPFqk%3D&reserved=0> > > <https://www.google.com/maps/search/13101%0D%0A+Columbia+Pike+%0D%0A+Silver%0D%0A+Spring,+MD?entry=gmail&source=g> > > -- > > *Error! Filename not specified.* > <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307123246&sdata=hspNepcNSicG01BlQPInlTrzCEDP7PrhsN5l0U9Qps4%3D&reserved=0> > > *Gyan Mishra* > > *Network Solutions Architect * > > > > *M 301 502-1347 13101 Columbia Pike > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307128228&sdata=Zb1%2FHn2R9VxjacjDLBnZIb97XOKZvEMRn7QJS2LUN0s%3D&reserved=0> > *Silver Spring, MD > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307133207&sdata=6ggk25pVaku9AIy6JyzPcXFYp9HxBqyxJUCsS2O7cOk%3D&reserved=0> > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307133207&sdata=6ggk25pVaku9AIy6JyzPcXFYp9HxBqyxJUCsS2O7cOk%3D&reserved=0> > > > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307138181&sdata=UYVHVeDZVxKw00dHyJFAM%2Ft4RrHG1Q5xsnfU2%2FQh89E%3D&reserved=0> > > <https://www.google.com/maps/search/13101%0D%0A+Columbia+Pike+%0D%0A+Silver%0D%0A+Spring,+MD?entry=gmail&source=g> > > -- > > [image: Image removed by sender.] > <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307143161&sdata=X%2FWFBYrgiaP3mP0VBmEbu9FmwKXpEBlXX%2F7N6IlbQMM%3D&reserved=0> > > *Gyan Mishra* > > *Network Solutions Architect * > > > > *M 301 502-1347 13101 Columbia Pike > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307148138&sdata=9KuBH1b%2FrqYPVPz1x0oh6WOhHTgJwGYW4oTqijSBVns%3D&reserved=0> > *Silver Spring, MD > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307153117&sdata=A%2F3aTskhdp8bYtLKDT9VQLCNNifuZm%2F3F2YRciVyH5E%3D&reserved=0> > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307158095&sdata=iW%2F09yn2PMwEzUAIXaBwVId9QrSNXbS1z7s8Vl9Ts78%3D&reserved=0> > > > > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%250D%250A%2BColumbia%2BPike%2B%250D%250A%2BSilver%250D%250A%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307163074&sdata=o6fgwcMsNL9oCFlB%2BUx%2FmtsvLiz%2BcUS5njwbbChsjlg%3D&reserved=0> > > <https://www.google.com/maps/search/13101%0D%0A+Columbia+Pike+%0D%0A+Silver%0D%0A+Spring,+MD?entry=gmail&source=g> > > -- > > > <https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.verizon.com%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307168050&sdata=mixHFVEqF4qQ4i%2B6JbES5OP1g%2FSb%2FrxDgIv9Rww4jf4%3D&reserved=0> > > *Gyan Mishra* > > *Network Solutions A**rchitect * > > > *M 301 502-1347 > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Fmaps%2Fsearch%2F13101%2BColumbia%2BPike%2B%250D%250A%2BSilver%2BSpring%2C%2BMD%3Fentry%3Dgmail%26source%3Dg&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4c12ec234b2a452db84408d7feb65044%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637257931307173031&sdata=zguxTuADiqiiAZ22lAVWQD8f6JNBQwU9hgD1QktRULs%3D&reserved=0>* > > -- <http://www.verizon.com/> *Gyan Mishra* *Network Solutions A**rchitect * *M 301 502-134713101 Columbia Pike *Silver Spring, MD
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