Re: [Lsr] IETF-116 LSR - IGP extensions for AdvertisingOffsetforFlex-Algorithm
Peter Psenak <ppsenak@cisco.com> Thu, 13 April 2023 06:59 UTC
Return-Path: <ppsenak@cisco.com>
X-Original-To: lsr@ietfa.amsl.com
Delivered-To: lsr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 17CF8C15152C for <lsr@ietfa.amsl.com>; Wed, 12 Apr 2023 23:59:41 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -9.598
X-Spam-Level:
X-Spam-Status: No, score=-9.598 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.com
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fDRSMaEk5JTO for <lsr@ietfa.amsl.com>; Wed, 12 Apr 2023 23:59:37 -0700 (PDT)
Received: from aer-iport-7.cisco.com (aer-iport-7.cisco.com [173.38.203.69]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4E6B5C15155C for <lsr@ietf.org>; Wed, 12 Apr 2023 23:59:36 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=73135; q=dns/txt; s=iport; t=1681369176; x=1682578776; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=YppCp+Tq+RkARFnu8NT30lZNkh8J5Wyuaak/1LzdPOM=; b=GWsO5dpshQp7GoZz0Y0qpzfMVuEnVQjfII+xdwu/8ruf3k6dwOyU0yM6 WrJFCIRyRjibPoz0KP+8xfeXTezQwK7LkUaDGkW4ncw4FxrgOyS71xG1J m0JFu5khpW0E/YHP/AEZHnVeAW3zCBATOTsDX0RWhb8idTTu1VNsxZ7+X U=;
X-IronPort-AV: E=Sophos;i="5.98,339,1673913600"; d="scan'208";a="4383656"
Received: from aer-iport-nat.cisco.com (HELO aer-core-11.cisco.com) ([173.38.203.22]) by aer-iport-7.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 13 Apr 2023 06:59:34 +0000
Received: from [10.60.140.52] (ams-ppsenak-nitro3.cisco.com [10.60.140.52]) by aer-core-11.cisco.com (8.15.2/8.15.2) with ESMTP id 33D6xXnr029717; Thu, 13 Apr 2023 06:59:34 GMT
Message-ID: <17e10c23-bc33-f184-8ace-bdeb65f18626@cisco.com>
Date: Thu, 13 Apr 2023 08:59:33 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.1
Content-Language: en-US
To: Liyan Gong <gongliyan@chinamobile.com>, Louis Chan <louisc@juniper.net>, Ketan Talaulikar <ketant.ietf@gmail.com>
Cc: Krzysztof Szarkowicz <kszarkowicz@juniper.net>, Robert Raszuk <robert@raszuk.net>, linchangwang <linchangwang.04414@h3c.com>, Acee Lindem <acee.ietf@gmail.com>, 程伟强 <chengweiqiang@chinamobile.com>, "Les Ginsberg(ginsbe" <ginsberg@cisco.com>, lsr <lsr@ietf.org>
References: <2afe643787bb4f6-00031.Richmail.00003020195207731471@chinamobile.com>
From: Peter Psenak <ppsenak@cisco.com>
In-Reply-To: <2afe643787bb4f6-00031.Richmail.00003020195207731471@chinamobile.com>
Content-Type: text/plain; charset="UTF-8"; format="flowed"
Content-Transfer-Encoding: 8bit
X-Outbound-SMTP-Client: 10.60.140.52, ams-ppsenak-nitro3.cisco.com
X-Outbound-Node: aer-core-11.cisco.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/lsr/CER_ibnet15rxGWRjdUpeGnLYac>
Subject: Re: [Lsr] IETF-116 LSR - IGP extensions for AdvertisingOffsetforFlex-Algorithm
X-BeenThere: lsr@ietf.org
X-Mailman-Version: 2.1.39
Precedence: list
List-Id: Link State Routing Working Group <lsr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/lsr>, <mailto:lsr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/lsr/>
List-Post: <mailto:lsr@ietf.org>
List-Help: <mailto:lsr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/lsr>, <mailto:lsr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 13 Apr 2023 06:59:41 -0000
Liyan, On 13/04/2023 06:50, Liyan Gong wrote: > Hi All， > > Thanks for your discussion, here are some informations to help > understanding better. > > > 1. About the application scenario, please refer to the following draft. > > https://datatracker.ietf.org/doc/draft-gong-teas-hierarchical-slice-solution/ <https://datatracker.ietf.org/doc/draft-gong-teas-hierarchical-slice-solution/> > > Flex-Algo can be associated with the level-1 network slice which > provides dynamic programming topology. > > The number of Flex-Algos is the same as the number of the level-1 > network slices. Maybe it can reach dozens. > > > 2. About the performance impact, Maybe we can think of it as advertising > massive routes through multi-pair neighbors in IGP domain. > > Since the advertising and flooding process occupy a lot of router > resources, Network changes can not be converged in time. > > This will result in wrong traffic forwarding. That is why there is > limitation on the number of routes in IGP domain. > > According to the anaysis by Changwang in the following email, SIDs take > up a big part. > > We think it is better if Flex-Algo can be scaled up by optimizing the > SIDs format without changing the IGP basic mechanism. I find the above claim incorrect and misleading. Network convergence is not the function of the a amount of data advertised per adjacency. thanks, Peter > > > Best Regards, > > Liyan > > > > > ----邮件原文---- > *发件人：*Louis Chan <louisc=40juniper.net@dmarc.ietf.org> > *收件人：*Ketan Talaulikar <ketant.ietf@gmail.com> > *抄 送: > *Krzysztof Szarkowicz <kszarkowicz@juniper.net>,Robert Raszuk <robert@raszuk.net>,linchangwang <linchangwang.04414@h3c.com>,Acee Lindem <acee.ietf@gmail.com>,Peter Psenak <ppsenak@cisco.com>,"程伟强" <chengweiqiang@chinamobile.com>,"Les Ginsberg(ginsbe" <ginsberg@cisco.com>,lsr <lsr@ietf.org> > *发送时间：*2023-04-13 12:31:12 > *主题：*Re: [Lsr] IETF- > 116 LSR - IGP extensions for Advertising OffsetforFlex-Algorithm > > Hi Ketan, > > Just a short response. > > If you remember ATM days, there are VP shaping/policing and VC > shaping/policing. It can solve quite complicated QOS problem. > > Here we are not doing the costly ATM again. > > With kind of hierarchical QOS readily available in ASIC today, it > potentially solves some complex multipoint to multipoint QOS problem. > > But first, it requires labeling the packet, like VCI and VPI. > > I am going to stop here because it would be too much to discuss. > > Rgds > > Louis > > *From:* Ketan Talaulikar <ketant.ietf@gmail.com> > *Sent:* Thursday, April 13, 2023 12:02 PM > *To:* Louis Chan <louisc@juniper.net> > *Cc:* Krzysztof Szarkowicz <kszarkowicz@juniper.net>; Robert Raszuk > <robert@raszuk.net>; linchangwang <linchangwang.04414@h3c.com>; Acee > Lindem <acee.ietf@gmail.com>; Peter Psenak <ppsenak@cisco.com>; 程伟 > 强 <chengweiqiang@chinamobile.com>; Les Ginsberg (ginsbe > <ginsberg@cisco.com>; lsr <lsr@ietf.org> > *Subject:* Re: [Lsr] IETF-116 LSR - IGP extensions for Advertising > Offset forFlex-Algorithm > > *[External Email. Be cautious of content]* > > Hi Louis, > > First we need to ascertain if it is necessary before we get things > flooded into IGPs. Then we can get to the evaluation of whether or > how "evil" it is. > > The VLAN analogy seems incorrect to me and a debate on that may be > orthogonal to this topic. I'll wait for the "necessity" to be first > described before taking a bite at this PIZZA ;-) > > Once again, thanks for your work on this document. > > Thanks, > > Ketan > > On Thu, Apr 13, 2023 at 9:15AM Louis Chan <louisc@juniper.net > <mailto:louisc@juniper.net>> wrote: > > Hi Ketan, > > First, I like “PIZZA” more than “VFA”, and at least it is closer > to “real” and tasty instead of “virtual” and boring. :) > > For VFA, it is just a further identification method. History has > VLAN first introduced in ethernet. People might think it was > already enough in that period. But later, market asked for > stacked vlan, and find its application. > > Having VFA/PIZZA might give more possibilities for future usage. > It is only ~30B advertisement per VFA per node, and it would not > be a big harm. And there is no further header overhead (or cell > tax) in forwarding plane, and make it easy of vendor interop. > This is more important. > > I have no intention to swamp IGP with control plane kind of > info, like QOS profile. My view is to leave IGP as slim as > possible for quick reaction to network changes. > > If it is a necessary evil, it should be minimum. My take would > be getting minimum but useful enough info into FAD. In this > case, the advertisement size is small, with ease of management. > That is what I refer to “good to have” info in previous email. > > Rgds > > Louis > > *From:* Ketan Talaulikar <ketant.ietf@gmail.com > <mailto:ketant.ietf@gmail.com>> > *Sent:* Thursday, April 13, 2023 12:06 AM > *To:* Krzysztof Szarkowicz <kszarkowicz@juniper.net > <mailto:kszarkowicz@juniper.net>> > *Cc:* Robert Raszuk <robert@raszuk.net > <mailto:robert@raszuk.net>>; linchangwang > <linchangwang.04414@h3c.com > <mailto:linchangwang.04414@h3c.com>>; Acee Lindem > <acee.ietf@gmail.com <mailto:acee.ietf@gmail.com>>; Peter > Psenak <ppsenak@cisco.com <mailto:ppsenak@cisco.com>>; 程伟强 > <chengweiqiang@chinamobile.com > <mailto:chengweiqiang@chinamobile.com>>; Louis Chan > <louisc@juniper.net <mailto:louisc@juniper.net>>; Les Ginsberg > (ginsbe <ginsberg@cisco.com <mailto:ginsberg@cisco.com>>; lsr > <lsr@ietf.org <mailto:lsr@ietf.org>> > *Subject:* Re: [Lsr] IETF-116 LSR - IGP extensions for > Advertising Offset forFlex-Algorithm > > *[External Email. Be cautious of content]* > > Hi Krzysztof, > > I got the impression that the use-case/need for these VFA SIDs > in the first place was to carry some indication in the packet > for local treatment at each hop (e.g,, bandwidth profile or QoS > treatment?) in the data path since the forwarding is based on > FlexAlgo. > > If not, then I am not sure that I follow the use-case or > motivation for VFA (or pizza ;-) as Louis calls it) in the first > place. > > Thanks, > > Ketan > > On Wed, Apr 12, 2023 at 9:28PM Krzysztof Szarkowicz > <kszarkowicz@juniper.net <mailto:kszarkowicz@juniper.net>> wrote: > > Hi Ketan, > > I agree with you. The draft doesn’t propose to carry > ’service bandwidth profile’ parameters in the IGP. > > The draft is dealing only with label/SID > assignment/generation and distribution. > > Thanks, > > Krzysztof > > On 2023 -Apr-12, at 17:49, Ketan Talaulikar > <ketant.ietf@gmail.com <mailto:ketant.ietf@gmail.com>> > wrote: > > *[External Email. Be cautious of content]* > > Hi Krzysztof, > > A further question is if it is necessary to carry this > "service bandwidth profile" information in the IGPs in > the first place. Why not indicate this just in the > packet? Wouldn't that be a better way to help scale > IGPs by not introducing this into IGPs in the first > place? ;-) > > One such simple solution is proposed by > https://datatracker.ietf.org/doc/draft-decraene-mpls-slid-encoded-entropy-label-id/ <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-decraene-mpls-slid-encoded-entropy-label-id/__;!!NEt6yMaO-gk!DxCsNxydz3b_s_iNl0j_6pyHLD1_vLYmeqwZbd_OBYdhfs3BBaQ8bIXbBsB-4Yigax-NkpPUA1EmCDwYmDNrSqU0Lg$> > > Thanks, > > Ketan > > On Wed, Apr 12, 2023 at 9:13PM Krzysztof Szarkowicz > <kszarkowicz=40juniper.net@dmarc.ietf.org > <mailto:40juniper.net@dmarc.ietf.org>> wrote: > > Hi, > > It is the question, if we could for example have > more than 20 (e.g. 200), for 200 different service > bandwidth guarantees (but having only one - or > handful - SPF calculation domains, where one SPF > calculation domain is one ‘legacy’ flex-algo ). The > challenge is with SPP calculations, once the number > of flex-algos goes high. > > Thanks, > > Krzysztof > > On 2023 -Apr-12, at 17:13, Robert Raszuk > <robert@raszuk.net <mailto:robert@raszuk.net>> > wrote: > > *[External Email. Be cautious of content]* > > Ok you can use 20 flex algos today with no > extension. Is going to another level of nesting > really necessary ? > > On Wed, Apr 12, 2023 at 4:52PM linchangwang > <linchangwang.04414@h3c.com > <mailto:linchangwang.04414@h3c.com>> wrote: > > Hi Acee > > An operator's backbone network is divided > into different flex algorithms planes > according to different SLA requirements of > users. > > A flex algo represents a service > requirement, such as bandwidth requirements. > > 20 flex algorithms represent 20 different > service bandwidth guarantees, corresponding > to different resource requirements. > > Thanks, > > Changwang lin > > *From:*Acee Lindem > [mailto:acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com>] > *Sent:* Wednesday, April 12, 2023 10:12 PM > *To:* Peter Psenak > *Cc:* linchangwang (RD); 程伟强; Louis Chan; > Les Ginsberg (ginsbe; lsr; Krzysztof Szarkowicz > *Subject:* Re: [Lsr] IETF-116 LSR - IGP > extensions for Advertising Offset > forFlex-Algorithm > > Hi Weiqiang, > > I’m also curious as to how you are using 20 > different flex algorithms. Is this just a > hypothetical scenario > > to illustrate the mathematics or do you have > an actual use case? > > On Apr 12, 2023, at 09:31, Peter Psenak > <ppsenak@cisco.com > <mailto:ppsenak@cisco.com>> wrote: > > Changwang, > > please see inline (##PP2): > > > On 12/04/2023 15:13, linchangwang wrote: > > Hi Peter > Please see inline [changwang lin]. > > We've met the same problem when applying > Flex Algo in SRv6 network. > > what problem exactly, can you please > describe it? > [changwang lin] > Advertisement size of per Flex-Algo Adj-SID > in the network > Related to F(# of node, # of FA, # of links) > For a node with 1,000 links and 20 Flex-Algo > n x 20 x 1000 > MPLS-SR：If n = 10 bytes, it is 200K bytes > SRv6： If n = 24 bytes, it is 400K+ bytes > If 500 nodes: > MPLS-SR：it is 200K*500 = 100000k bytes > SRv6： it is 400K+ * 500 = 200000k bytes > If interface mtu=1500, lsp length = 1497 > LSPs num: > MPLS-SR：10000k bytes/1497 = 66800 lsps > SRv6： 20000k bytes/1497 = 160320 lsps > The number of LSPs is too large, and IS-IS > needs to periodically refresh LSPs, > resulting in a decrease in ISIS performance > and unstable network operation. > > > ##PP2 > above is hardly a realistic estimation. > > In a network with 1k nodes, not every node > will have 1k links. > > Advertising large number of LSPs is not > caused by Adj-SIDs. > With TE enabled the amount of data flooded > per link is larger than advertisement of the > 20 Adj-SID. The problem you are highlighting > is not specific to Adj-SIDs, it's generic. > > LSP refresh time can be set to 18 hours and > any reasonable implementation does not > refresh all LSPs at the same time. > > So we need to optimize on the control > surface to save LSP space. > > > ##PP2 > with all the respect, I don't agree. The > problem as you described it does not exist. > > Through the optimization notification > mechanism mentioned in these two documents, > we have greatly saved LSP space for IS-IS > and improved the performance of IS-IS flex > algo in large-scale networking. > At the same time, through the VFA mechanism, > in other non flex algo application scenarios, > such as network slicing scenarios, the LSP > space of IS-IS can also be saved > > > ##PP2 > it seems to me you are trying to fix the > implementation problem with the protocol > changes, which is never a good idea. > > thanks, > Peter > > thanks, > Changwang lin > -----Original Message----- > From: Lsr [mailto:lsr-bounces@ietf.org > <mailto:lsr-bounces@ietf.org>] On Behalf Of > Peter Psenak > Sent: Wednesday, April 12, 2023 7:10 PM > To: 程伟强; Louis Chan; Les Ginsberg > (ginsbe; Acee Lindem > Cc: lsr; Krzysztof Szarkowicz > Subject: Re: [Lsr] IETF-116 LSR - IGP > extensions for Advertising Offset > forFlex-Algorithm > Weiqiang, > please see inline (##PP): > On 12/04/2023 12:05, 程伟强wrote: > > Hi Louis and Les, > > > My two cents from operator perspective. > > > We've met the same problem when applying > Flex Algo in SRv6 network. > > what problem exactly, can you please > describe it? > [changwang lin] > Advertisement size of per Flex-Algo Adj-SID > in the network > Related to F(# of node, # of FA, # of links) > For a node with 1,000 links and 20 Flex-Algo > n x 20 x 1000 > MPLS-SR：If n = 10 bytes, it is 200K bytes > SRv6： If n = 24 bytes, it is 400K+ bytes > If 500 nodes: > MPLS-SR：it is 200K*500 = 100000k bytes > SRv6： it is 400K+ * 500 = 200000k bytes > If interface mtu=1500, lsp length = 1497 > LSP num: > MPLS-SR：10000k bytes/1497 = 66800 lsps > SRv6： 20000k bytes/1497 = 160320 lsps > The number of LSPs is too large, and IS-IS > needs to periodically refresh LSPs, > resulting in a decrease in ISIS performance > and unstable network operation. > So we need to optimize on the control > surface to save LSP space. > Through the optimization notification > mechanism mentioned in these two documents, > we have greatly saved LSP space for IS-IS > and improved the performance of IS-IS flex > algo in large-scale networking. > At the same time, through the VFA mechanism, > in other non flex algo application scenarios, > such as network slicing scenarios, the LSP > space of IS-IS can also be saved > > > > As the number of slices and the scale of the > network increases, the > convergence issue which is caused by SIDs > advertising and flooding > becomes more and more serious. > > > Due to the problem, it is impossible to > apply Flex-Algo in the large > network, such as the network with more than > 1000 routers. > > flex-algo has been successfully deployed in > a networks that have more > that 1k nodes. > Maybe you want deploy the flex-algo for > something that it was not > designed for. > > > > I believe Louis'draft provides a good idea > to resolve this problem. > Similar solution for SRv6 SIDs is described > in another draft. > > Again, what problem exactly? > From what I see the drafts tries to pack > algo SIDs to save space in > LSP. I don't see how it helps to to deploy > flex-algo in a large scale > network. > thanks, > Peter > > > > About the SIDs assignment, I think it is > better to have a scheduled > assignment than a random assignment as Les > mentioned. > > > [1] > https://datatracker.ietf.org/doc/draft-cheng-lsr-isis-srv6-sid-block/ <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-cheng-lsr-isis-srv6-sid-block/__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUND7v7my7$> > <https://datatracker.ietf.org/doc/draft-cheng-lsr-isis-srv6-sid-block/ <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-cheng-lsr-isis-srv6-sid-block/__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUND7v7my7$>> > > > > Thanks, > > Weiqiang Cheng > > > > ----邮件原文---- > *发件人：*Louis Chan > <louisc=40juniper.net@dmarc.ietf.org > <mailto:40juniper.net@dmarc.ietf.org>> > *收件 > 人：*"Les Ginsberg (ginsberg)" > <ginsberg@cisco.com > <mailto:ginsberg@cisco.com>>,Acee Lindem > <acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com>> > *抄 送: > *lsr <lsr@ietf.org > <mailto:lsr@ietf.org>>,Krzysztof Szarkowicz > <kszarkowicz@juniper.net > <mailto:kszarkowicz@juniper.net>>,Weiqiang > Cheng <chengweiqiang@chinamobile.com > <mailto:chengweiqiang@chinamobile.com>> > *发送时间：*2023-04-12 10:45:56 > *主题：*Re: [Lsr] IETF- > 116 LSR - IGP extensions for > Advertising Offset forFlex-Algorithm > > Hi Les, > > Thanks for the prompt reply. Please see > inline for clarification [lc2]. > > /Louis > > *From:* Les Ginsberg (ginsberg) > <ginsberg@cisco.com <mailto:ginsberg@cisco.com>> > *Sent:* Tuesday, April 11, 2023 11:03 PM > *To:* Louis Chan <louisc@juniper.net > <mailto:louisc@juniper.net>>; Acee Lindem > <acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com>> > *Cc:* lsr <lsr@ietf.org > <mailto:lsr@ietf.org>>; Krzysztof Szarkowicz > <kszarkowicz@juniper.net > <mailto:kszarkowicz@juniper.net>>; Weiqiang > Cheng > <chengweiqiang@chinamobile.com > <mailto:chengweiqiang@chinamobile.com>> > *Subject:* RE: [Lsr] IETF-116 LSR - IGP > extensions for Advertising > Offset for Flex-Algorithm > > *[External Email. Be cautious of content]* > > Louis - > > Please see inline. > > > -----Original Message----- > > > From: Louis Chan <louisc@juniper.net > <mailto:louisc@juniper.net> > <mailto:louisc@juniper.net > <mailto:louisc@juniper.net>>> > > > Sent: Monday, April 10, 2023 11:01 PM > > > To: Les Ginsberg (ginsberg) > <ginsberg@cisco.com <mailto:ginsberg@cisco.com> > <mailto:ginsberg@cisco.com > <mailto:ginsberg@cisco.com>>>; Acee Lindem > > > <acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com> > <mailto:acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com>>> > > > Cc: lsr <lsr@ietf.org > <mailto:lsr@ietf.org> <mailto:lsr@ietf.org > <mailto:lsr@ietf.org>>>; Krzysztof > Szarkowicz <kszarkowicz@juniper.net > <mailto:kszarkowicz@juniper.net> > <mailto:kszarkowicz@juniper.net > <mailto:kszarkowicz@juniper.net>>>; > > > Weiqiang Cheng > <chengweiqiang@chinamobile.com > <mailto:chengweiqiang@chinamobile.com> > <mailto:chengweiqiang@chinamobile.com > <mailto:chengweiqiang@chinamobile.com>>> > > > Subject: RE: [Lsr] IETF-116 LSR - > IGP extensions for Advertising > Offset for > > > Flex-Algorithm > > > > > > Hi Les, > > > > > > Thanks for your questions. Please > see inline [lc] below. > > > > > > /Louis > > > > > > -----Original Message----- > > > From: Les Ginsberg (ginsberg) > <ginsberg@cisco.com <mailto:ginsberg@cisco.com> > <mailto:ginsberg@cisco.com > <mailto:ginsberg@cisco.com>>> > > > Sent: Saturday, April 8, 2023 7:34 AM > > > To: Acee Lindem <acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com> > <mailto:acee.ietf@gmail.com > <mailto:acee.ietf@gmail.com>>>; Louis Chan > <louisc@juniper.net <mailto:louisc@juniper.net> > <mailto:louisc@juniper.net > <mailto:louisc@juniper.net>>> > > > Cc: lsr <lsr@ietf.org > <mailto:lsr@ietf.org> <mailto:lsr@ietf.org > <mailto:lsr@ietf.org>>> > > > Subject: RE: [Lsr] IETF-116 LSR - > IGP extensions for Advertising > Offset for > > > Flex-Algorithm > > > > > > [External Email. Be cautious of content] > > > > > > > > > OK - since Acee opened the door - > here are some comments from me - > > > starting with the most important. > > > > > > (BTW - I still have limited > enthusiasm for this draft.) > > > > > > 1)The proposal places some > restrictions on how operators > provision their > > > network in terms of assigning SIDs > and reserving space for future > > > assignments. > > > If operators do not use compatible > assignment schemes, then this > will never > > > get deployed. It is therefore not > enough to come with a nice idea > - you must > > > have some enthusiasm from the > operator community. > > > > > > > > > [lc] If the operator only wants to > deploy flex-algo, there is no > change in their > > > Node-sid numbering scheme. For the > Adj-sid, these are local > labels with local > > > significant only, and there is no > need for any special planning > for Adj-sid, > > > unless you are suggesting they want > to make fixed assignment of > Adj-sid > > > label for each link. Even with > fixed, the proposed draft has > benefit on that. I > > > will explain later. > > > > > [LES:] Let's discuss this in the > context of prefix-sids - the same > applies to adj-sids. > > Today (i.e., in the absence of your > proposal) an operator is free to > assign any label within the SRGB for a > given prefix/algo pair so > long as it is not assigned to some > other prefix/algo context. > > Your proposal places some new > restrictions. Now, for a given > flex-algo, whenever an operator assigns > a given label for a prefix > in Algo 0 (call it Label-A0), they must > guarantee that > "Label-A0+offset" for an advertised > flex-algo specific offset is > available to be assigned for the > prefix/flex-algo pair - and this > must be true for all prefixes > advertised in algo 0. > > This is certainly possible to do, but > is not guaranteed to be the > case in current deployments. > > For example - and this is only an > example...today an operator might > utilize a provisioning tool to assign > prefix-sids for all supported > algorithms on all nodes in the network. > > To do this, the tool might maintain a > database of assigned labels. > When provisioning a new > node/prefix/algorithm, the logic in the tool > might simply take the next available > label in the database. > > The result of this would not be > consistent with the requirements of > your draft. > > Which is why I say in order to deploy > the extension you propose, > such an operator would have to modify > its provisioning tool. > > [lc2] There might be some > misunderstanding of our proposal. Let me > give some examples. > > Case 1: Flex-Algo only > > Prefix offset advertisement: “no” > > Adj-sid offset advertisement: yes > > In slide 8’s example, FA129 is using > label “402001”, and the > advertisement of this label is using > existing methods. > > e.g. SRGB = 400000-460000 > > FA129: index 2001 (preferred value), or > one can choose 111, 222 > > FA130 (new): index 3001 (preferred > value), or 333, 4444 > > This does not change how the operator > to assign label for prefix-sid > with their current method. Any > index/label could be used for FA > prefix within SRGB. > > The only change is the Adj-sid label > allocation, but this “mostly” > is only “local” to one node. There is > no effect on global label > allocation. > > This draft will be compatible to what > operators are doing today. > > Case 2: VFA only > > Prefix offset advertisement: yes > > Adj-sid offset advertisement: yes > > I agree, with VFA, there would be > impact to global allocation to > node-sid/prefix-sid. But VFA is a > totally new concept. No one has > deployed that yet. > > There is no impact to operators which > stick to deploy only Flex-algo. > > Other case: Flex-Algo w/o Adj-sid offset > > Continue the example of > Case#1 above > > Another FA131 is added, > but no Adj-sid offset is > advertised > > The question would be > > * > > Either allow this configuration, > and FA131 will fallback using > Algo 0’s adj-sid > > * > > Or, disallow this configuration > > I tend to “allow” such configuration > with mix of FA129, FA130 (with > adj-sid offset) and FA131 (w/o adj-sid > offset) > > [/lc2] > > Could this be done? Sure. > > Do operators want to do this? I do not > know. > > But since this would be necessary in > order to use your proposed > extension, it is necessary to gauge > operator enthusiasm for making > such changes in order to know whether > there is any point in > proceeding with your proposal. > > > In slide 8 of the below presentation > > > > https://datatracker.ietf.org/meeting/116/materials/slides-116-lsr-03-ietf116- <https://urldefense.com/v3/__https:/datatracker.ietf.org/meeting/116/materials/slides-116-lsr-03-ietf116-__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNBlx2nlh$> <https://urldefense.com/v3/__https:/datatracker.ietf.org/meeting/116/materials/slides-116-lsr-03-ietf116-igp-adv-offset-01__;!!NEt6yMaO-gk!Bl7Swe9ql9VT0qGkD6FoZZzTWT2fmIx55eSncdmMgoCJetJ5-80micuqnqk79yewGB-BleOfrYpSjfI$ <https://urldefense.com/v3/__https:/datatracker.ietf.org/meeting/116/materials/slides-116-lsr-03-ietf116-igp-adv-offset-01__;!!NEt6yMaO-gk!Bl7Swe9ql9VT0qGkD6FoZZzTWT2fmIx55eSncdmMgoCJetJ5-80micuqnqk79yewGB-BleOfrYpSjfI$>> > > > igp-adv-offset-01 > <https://urldefense.com/v3/__https:/datatracker.ietf.org/meeting/116/materials/slides-116-lsr-03-ietf116-igp-adv-offset-01__;!!NEt6yMaO-gk!Bl7Swe9ql9VT0qGkD6FoZZzTWT2fmIx55eSncdmMgoCJetJ5-80micuqnqk79yewGB-BleOfrYpSjfI$ <https://urldefense.com/v3/__https:/datatracker.ietf.org/meeting/116/materials/slides-116-lsr-03-ietf116-igp-adv-offset-01__;!!NEt6yMaO-gk!Bl7Swe9ql9VT0qGkD6FoZZzTWT2fmIx55eSncdmMgoCJetJ5-80micuqnqk79yewGB-BleOfrYpSjfI$>> > > > > > > FA129 is a prefix-sid (400201) > allocated by operator, and it can > be any label. > > > There is no connection to how > Adj-sid is derived. > > > Per Flex-Algo adj-sid assignment is > not affecting network wide label > > > assignment from operation > perspective. Each node could have > different local > > > block for such adj-sid assignment. > One might need to estimate > total possible > > > number of link in one chassis for > such allocation, or it could be > estimated by > > > OS software itself. I also mentioned > in the session, if there is > 100 x FA with > > > 1000 links (high end), it is only > 100k labels. Is it difficult to > allocate such. > > [LES:] Your proposal does not reduce > the number of labels which need > to be "allocated" and installed in > forwarding, it only reduces the > number of bytes used to advertise this > information in LSPs/LSAs. > > [lc2] You are correct. > > I think, at the same time, it helps > reducing time for global > convergence since the advertisement > size is smaller, especially in > network with long diameter with multi-hops. > > Also, in > https://datatracker.ietf.org/doc/draft-ietf-lsr-isis-fast-flooding/ <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-ietf-lsr-isis-fast-flooding/__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNHGf6W4I$> > <https://datatracker.ietf.org/doc/draft-ietf-lsr-isis-fast-flooding/ <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-ietf-lsr-isis-fast-flooding/__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNHGf6W4I$>> (which you participated in) > > >>> > > As IS-IS is deployed in greater > scale both in the number of nodes in > > an area and in the number of > neighbors per node, the impact of the > > historic flooding rates becomes > more significant. Consider the > > bringup or failure of a node with > 1000 neighbors. This will result > > in a minimum of 1000 LSP updates. > At typical LSP flooding rates > used > > today (33 LSPs/second), it would > take 30+ seconds simply to send the > > updated LSPs to a given neighbor. > Depending on the diameter of the > > network, achieving a consistent > LSDB on all nodes in the network > > could easily take a minute or more. > > <<< > > This proposed draft will certainly help. > > [/lc2] > > > > > > So, this is why I do not understand > your question in full. > > > > > > If the operator plans to use VFA, > that would be a different > discussion. VFA, > > > today, does not exist in deployment. > > > > > [LES:] My comments here have nothing to > do with VFA. > > > [/lc] > > > > > > Have you discussed this idea with > any operators? > > > > > > [lc] I include Wei-qiang from China > mobile in this thread. He has > shown his > > > need on this kind of solution. > Maybe, he could give his > perspective here. [/lc] > > > > > > If so, what has been their response? > > > If they are open to the idea, how > might they migrate from their > existing > > > assignment schemes to an assignment > scheme compatible with the > > > proposal? > > > > > > These are questions that need to be > answered before considering > this idea. > > > > > > [lc] In slide 8, if you see these > label numbers > > > > > > Prefix-sid: 400001, 402001, 406001, > 407001 > > > Adj-sid: 32, 2032, 6032, 7032 > > > > > > From operator perspective or > troubleshooting perspective, value > xxx001 > > > represent the same node, and value > x032 represent the same link. This > > > makes things more organized and > easier to understand. > > > > > > If all are random labels, I do not > see any benefit at all. > > > [/lc] > > [LES:] I am not commenting on whether > the label assignment scheme > you propose is better or worse than any > other. > > I am only pointing out that you are > imposing new restrictions on how > labels are allocated. > > As you are not in charge of how > operators provision their networks > (nor am I), it is presumptuous of you > to think that simply because > you think this is a better way to do > things that operators will be > happy to modify their existing networks > to conform to your proposed > restrictions. > > This isn’t academia - you need to vet > this with the operator community. > > [lc2] Please refer to the examples at > the top. The picture should be > clear by now. There is no restriction > to what is deployed today. [/lc2] > > > > > > 2)Section 5 Compatibilty > > > > > > There is no "compatibility" with > legacy nodes - because all nodes > in the > > > network have to have a consistent > understanding of what SID is > assigned to a > > > given context (for prefixes and > adjacencies) since they might > need to install > > > forwarding entries for that context. > > > I do not see any point in deploying > this until all nodes support > it. If you did do > > > so, you would need to advertise old > and new forms - which does the > > > opposite of what you are trying to > achieve. Instead of reducing > LSP space > > > used you would increase it. > > > > > > [lc] If the operator just plans to > use only Flex-Algo, and no > VFA, it should be > > > compatible with legacy > implementation. If legacy nodes do not > understand > > > adj-sid offset notation, these nodes > could just ignore it. The > forwarding > > > plane should work with co-existence > of old and new nodes. Per > flex-algo adj- > > > sid is only local significant to one > node. New nodes should > detect whether > > > legacy nodes exist in the network > via such new extension > advertisement. > > > And new nodes should use only algo 0 > adj-sid from legacy nodes > for any TI- > > > LFA. > > [LES:] Consider a network of 100 nodes. > > Let's say the "left-hand-side" of the > network consist of legacy > nodes who do not understand your new > advertisements. > > The "right-hand-side" of the network > consists of upgraded nodes who > support the new advertisements. > > Consider nodes PE-LEFT and PE-RIGHT. > > PE-RIGHT advertises a prefix-SID of > 1000 for 2.2.2.2/32 > <https://urldefense.com/v3/__http:/2.2.2.2/32__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNEj8LL78$>, and an > offset of 1000 for flex-algo 128. > > PE-LEFT supports flex-algo 128 and > wants to install a forwarding > entry for 2.2.2.2 for flex-algo 128. > > It looks in the LSPs originated by > PE-RIGHT. It does not see any > assigned SID for 2.2.2.2/32 > <https://urldefense.com/v3/__http:/2.2.2.2/32__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNEj8LL78$> flex-algo 128. > > It cannot create a forwarding entry. > And neither can any other node > in the left hand side of the network. > > When PE-RIGHT stops advertising the > explicit prefix SID for > 2.2.2.2/32 > <https://urldefense.com/v3/__http:/2.2.2.2/32__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNEj8LL78$> Algo 128, all legacy nodes are unable to create > forwarding entries for the prefix/algo > tuple. > > This isn’t backwards compatible. > > In general, you cannot advertise > information legacy nodes require in > a new container that legacy nodes do > not understand and claim that > you are backwards compatible. > > [lc2] Please refers to the examples for > clarification. > > 1. > > For existing Flex-Algo deployment, > it would be compatible. There > is no change in the container > format on how prefix-sid > 2.2.2.2/32 > <https://urldefense.com/v3/__http:/2.2.2.2/32__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNEj8LL78$> in FA128 is advertised. > > 1. > > For new VFA, it would not be > compatible. But….it does not mean > that we could not have VFA running > in the same network. > > There could be procedures to enhance > such. With your example, one > workaround could be: > > For VFA 600, PE-RIGHT detects that > PE-LEFT does not participate in > VFA600 (due to no offset advertisement > seen), > > * > > Either, it spawns new CSPF for > VFA600 instead of sharing FA129’s > result. Bypass PE-LEFT as a result. > > * > > Or, it uses legacy node FA129 > prefix-sid and adj-sid as > replacement (note: this method > needs more comment) > > In either ways, VFA600 could work > without issue even with legacy > nodes co-existence. > > After PE-LEFT upgraded, VFA600 would be > using FA129 CSPF result > instead, and save CPU resources in each > node. > > Another question: do we need FAD for > VFA600? Currently, no. Not > mandatory. > > But it could be considered if “good to > have” parameters are passed > along with FAD. > > [/lc2] > > > > > > I do not see a major problem. Please > give me an example to > illustrate your > > > concern if possible. > > > > > > Of course, we need to do double > check on the claim and possibly lab > > > verification to see if the backward > compatibility could be > achieved. It could > > > be vendor specific. > > > > > > [/lc] > > > > > > > > > What does deserve discussion is a > "hitless migration strategy". > When full > > > support is available, if you were to > switch to the new scheme, > you would > > > want to do so without changing any > existing SIDs as this would avoid > > > forwarding disruption. Which means > operators would have to modify > their > > > SID assignment scheme in advance of > deploying the new scheme. > > > > > > [lc] For VFA, there would be issue > for legacy nodes. I agree. In > this case, > > > solution could be > > > - either have a fallback > plan for newer nodes if > detection of legacy nodes > > > exist in the network. E.g. spawn new > CSPF > > > - or, totally not to deploy > VFA unless all nodes are > upgraded. > > > > > > Section 5 is not updated with VFA > inclusion. > > [LES:] My comments have nothing to do > with VFA. > > Please reconsider them after you have > understood the backwards > compatibility issues. > > > > > > [/lc] > > > > > > 3)Virtual Flex Algorithm > > > > > > You have introduced a new concept > with very little explanation of > what it is > > > nor how it can be supported. > > > For example, how would we determine > which nodes support a given VFA? > > > Since the algorithm value must be > greater than 255, it cannot be > advertised in > > > the existing SR Algorithm sub-TLV. > > > > > > If you are serious about this idea, > please provide a more complete > > > discussion. > > > > > > [lc] We could illustrate application > examples in next > presentation. For > > > ethernet, we have port, and then we > have VLAN and stacked vlan. > History > > > has some hints on this. > > > > > [LES:] You are writing a normative > specification. Hoping that all > readers/implementors have the same > "intuition" isn’t sufficient. > > Les > > > [/lc] > > > > > > 4)Section 4.3 > > > > > > "R" and "N" flags are now defined in > prefix attributes sub-TLV > (RFC7794) > > > They were originally defined in the > SR sub-TLV because RFC 7794 > did not exist > > > at the time. > > > The only reason they continue to > exist in RFC 8667 is for backwards > > > compatibility with early > implementation of SR-MPLS based on early > drafts of > > > what became RFC 8667. > > > Please do not introduce them in new > sub-TLVs - there is no need. > > > > > > [lc] noted with thanks [/lc] > > > > > > 5)ADJ-SIDs are NOT allocated from > the SRGB as they are local in > scope. > > > They MAY be allocated from the SRLB > - or outside either GB range. > > > Please correct the document in this > regard. > > > > > > [lc] noted [/lc] > > > > > > Les > > > > > > > -----Original Message----- > > > > From: Lsr <lsr-bounces@ietf.org > <mailto:lsr-bounces@ietf.org> > <mailto:lsr-bounces@ietf.org > <mailto:lsr-bounces@ietf.org>>> > On Behalf Of Acee Lindem > > > > Sent: Friday, April 7, 2023 11:43 AM > > > > To: Louis Chan <louisc@juniper.net > <mailto:louisc@juniper.net> > <mailto:louisc@juniper.net > <mailto:louisc@juniper.net>>> > > > > Cc: lsr <lsr@ietf.org > <mailto:lsr@ietf.org> <mailto:lsr@ietf.org > <mailto:lsr@ietf.org>>> > > > > Subject: Re: [Lsr] IETF-116 LSR - > IGP extensions for Advertising > > > > Offset for Flex-Algorithm > > > > > > > > Hi Louis, > > > > > > > > In the interest of initiating > discussion, I would like to > propose the > > > > term "Flex Algorithm Traffic Class > (FATC)" for the sub-division of > > > > flex-algorithm traffic referred to > in the draft as “Virtual > Flex Algorithm”. > > > > > > > > Also, in your terminology, you > refer referred to TLVs and > fields with > > > > simply “Algorithm” when RFC 9350 > uses “Flex Algorithm”. > > > > > > > > Thanks, > > > > Acee > > > > > > > > > > > > > > > > > _______________________________________________ > > > > Lsr mailing list > > > > Lsr@ietf.org <mailto:Lsr@ietf.org> > <mailto:Lsr@ietf.org <mailto:Lsr@ietf.org>> > > > > > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/lsr_ <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr_> <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr_ <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr_>> > > > > _;!!NEt6yMaO-gk!B9ufrV6k- > > > > c7mtP9JUiXbrF3NCkZ15_UMLBjV_fnJovfz18M5VkkI2F > > > > EoixpkxsfMnbqwbR0bpHgoS9E$ > > > > > > Juniper Business Use Only > > Juniper Business Use Only > > > Juniper Business Use Only > > _______________________________________________ > Lsr mailing list > Lsr@ietf.org <mailto:Lsr@ietf.org> > https://www.ietf.org/mailman/listinfo/lsr > <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNLUwWHuZ$> > ------------------------------------------------------------------------------------------------------------------------------------- > 本邮件及其附件含有新华三集团的保密信息，仅限 > 于发送给上面地址中列出 > 的个人或群组。禁止任何其他人以任何形式使用 > （包括但不限于全部或部分地泄露、复制、 > 或散发）本邮件中的信息。如果您错收了本邮件， > 请您立即电话或邮件通知发件人并删除本 > 邮件！ > This e-mail and its attachments contain > confidential information from New H3C, which is > intended only for the person or entity whose > address is listed above. Any use of the > information contained herein in any way > (including, but not limited to, total or partial > disclosure, reproduction, or dissemination) > by persons other than the intended > recipient(s) is prohibited. If you receive > this e-mail in error, please notify the sender > by phone or email immediately and delete it! > > _______________________________________________ > Lsr mailing list > Lsr@ietf.org <mailto:Lsr@ietf.org> > https://www.ietf.org/mailman/listinfo/lsr > <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr__;!!NEt6yMaO-gk!GCoxXhuL7ryqRodFUI2f-GPQa1_Vjs9WLIB_XJtQUiKVcm6Yrxqx5p-_PmGOQFNseVacNf7mx4QUNLUwWHuZ$> > > _______________________________________________ > Lsr mailing list > Lsr@ietf.org <mailto:Lsr@ietf.org> > https://www.ietf.org/mailman/listinfo/lsr > <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr__;!!NEt6yMaO-gk!DxCsNxydz3b_s_iNl0j_6pyHLD1_vLYmeqwZbd_OBYdhfs3BBaQ8bIXbBsB-4Yigax-NkpPUA1EmCDwYmDMh734fjw$> > > Juniper Business Use Only > > > Juniper Business Use Only >
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Liyan Gong
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Peter Psenak
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Louis Chan
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Christian Hopps
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Louis Chan
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Christian Hopps
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… Christian Hopps
- Re: [Lsr] IETF-116 LSR - IGP extensions for Adver… linchangwang
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Les Ginsberg (ginsberg)
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Louis Chan
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Louis Chan
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Christian Hopps
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Louis Chan
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Christian Hopps
- Re: [Lsr] IETF-116 LSR - IGP extensions forAdvert… Louis Chan