Re: [Lsr] LSR WG Adoption Poll for "Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints" - draft-hegde-lsr-flex-algo-bw-con-02
Peter Psenak <ppsenak@cisco.com> Mon, 24 May 2021 18:58 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 2070D3A3290; Mon, 24 May 2021 11:58:21 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -11.9
X-Spam-Level:
X-Spam-Status: No, score=-11.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, 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_DNSWL_MED=-2.3, SPF_NONE=0.001, URIBL_BLOCKED=0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8ayhxcKN4bxf; Mon, 24 May 2021 11:58:15 -0700 (PDT)
Received: from aer-iport-3.cisco.com (aer-iport-3.cisco.com [173.38.203.53]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 31C833A328E; Mon, 24 May 2021 11:58:15 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=4826; q=dns/txt; s=iport; t=1621882695; x=1623092295; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=pNAK7kE59jQS0YU7zoKtmlHVbScVvPNDnAnF3cG4SEU=; b=hRM94G8+jLFE9Eq2Ru9HJSHPBgfiW/tj+vaVlquoDeQzMFqiEuHDpgf4 VoLusN1wNZHb49nKz/I0tdpj0rHAGK8fwVdrd63bAVa0i59uyo4rNVjxZ qkMTz7CkWRcIcToTwrBg/DyzHxdo1L12CZ6CvXc62xPerSt1s6Sj8seMS E=;
X-IronPort-AV: E=Sophos;i="5.82,325,1613433600"; d="scan'208";a="33874517"
Received: from aer-iport-nat.cisco.com (HELO aer-core-3.cisco.com) ([173.38.203.22]) by aer-iport-3.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 24 May 2021 18:58:13 +0000
Received: from [10.60.140.52] (ams-ppsenak-nitro3.cisco.com [10.60.140.52]) by aer-core-3.cisco.com (8.15.2/8.15.2) with ESMTP id 14OIwC6Y029342; Mon, 24 May 2021 18:58:13 GMT
To: Tony Li <tony.li@tony.li>, Ketan Jivan Talaulikar <ketant@cisco.com>
Cc: "Acee Lindem (acee)" <acee=40cisco.com@dmarc.ietf.org>, "lsr@ietf.org" <lsr@ietf.org>, "draft-hegde-lsr-flex-algo-bw-con@ietf.org" <draft-hegde-lsr-flex-algo-bw-con@ietf.org>
References: <0BAE6DBA-04A3-4A3A-A1E3-14EFAA0FBE68@cisco.com> <MW3PR11MB4570FB10A5788FDA3BBA6C91C1269@MW3PR11MB4570.namprd11.prod.outlook.com> <AE6570D7-062E-4F8A-92E8-120FA52D4785@tony.li>
From: Peter Psenak <ppsenak@cisco.com>
Message-ID: <0cbe5dec-0278-850f-df08-692cc34880e7@cisco.com>
Date: Mon, 24 May 2021 20:58:12 +0200
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.9.1
MIME-Version: 1.0
In-Reply-To: <AE6570D7-062E-4F8A-92E8-120FA52D4785@tony.li>
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Language: en-US
Content-Transfer-Encoding: 8bit
X-Outbound-SMTP-Client: 10.60.140.52, ams-ppsenak-nitro3.cisco.com
X-Outbound-Node: aer-core-3.cisco.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/lsr/2Lzc647MKZPbXuA5gu8Am9ZRY_M>
Subject: Re: [Lsr] LSR WG Adoption Poll for "Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints" - draft-hegde-lsr-flex-algo-bw-con-02
X-BeenThere: lsr@ietf.org
X-Mailman-Version: 2.1.29
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: Mon, 24 May 2021 18:58:21 -0000
Hi Tony, On 24/05/2021 20:44, Tony Li wrote: > > Hi Ketan, > >> In general, I support the adoption of this document. There is, >> however, one specific point which is not clear to me (8) below that I >> would appreciate some clarity on before adoption. > > > As the chairs have noted, adoption is binary and not contingent upon > rough consensus on the content, just on rough consensus on the interest. > > > >> 1. Why is the Generic Metric type in ISIS limited to 3 byte size? >> OSPF allows 4 byte size and so why not the same for ISIS? >> Elsewhere in the document, I do see MAX METRIC being referred to >> as 4,261,412,864. > > > Because I’m a lazy sod. > > It’s far easier to detect metric overflow on three byte values than four > byte values. True, four byte is not impossible, but it’s just quick and > easy with three byte values. Adding a fourth byte would add range to > the metric space, but in practice, this seemed like it was not really > relevant. Most areas are not a very high diameter and the need for > detailed metric distinctions has not been that high. Thus, we went with > a 3 byte metric in RFC 5305 (sec 3.7) and that seems to work. > >> 1. >> 2. Would be good to cover the max-metric considerations for the >> Generic Metric. Similar >> tohttps://datatracker.ietf.org/doc/html/draft-ietf-lsr-flex-algo-15#section-15.3 > > > Fair > > >> 2. >> 3. Since the draft is covering FlexAlgo, I would have expected that >> Generic Metric is carried only in the ASLA and this document >> specifies usage only for the FA application. Later this can be >> also used/extended for other applications but still within ASLA. >> Keeping an option of advertising both outside and within the ASLA >> is problematic – we will need precedence rules and such. I prefer >> we avoid this complication. > > > We preferred avoiding ASLA. we are not avoiding ASLA. We allow the ISIS Generic Metric sub-TLV to be sent inside or outside ASLA. For flex-algo purposes we mandate it to be in ASLA. That's all what we need for the purpose of this draft. The rest is for future. > > >> 3. >> 4. For the newly proposed FAD b/w constraints, I would suggest the >> following names for the constraint sub-TLVs where the b/w value >> signalled by all is compared with the Max Link B/w attribute. This >> is just to make the meaning, at least IMHO, more clear. >> 1. Exclude Higher Bandwidth Links >> 2. Exclude Lower Bandwidth Links >> 3. Include-Only Higher Bandwidth Links >> 4. Include-Only Lower Bandwidth Links >> 5. Similar naming for the FAD delay constraints as well would help. >> Though I can only think of the use of “exclude” for links above a >> certain delay threshold to be more practical but perhaps others >> might eventually be required as well? > > > Thank you for the suggestions. > > >> 5. >> 6. For the Max B/w Link attribute and its comparison with the FAD b/w >> constraints, I see the reference to ASLA. While in OSPF >> max-bandwidth is not allowed in ASLA >> -https://datatracker.ietf.org/doc/html/rfc8920#section-7, in case >> of ISIS also, it is not really appropriate for use within ASLA >> -https://datatracker.ietf.org/doc/html/rfc8919#section-4.2.1? > > > I’m sorry, I don’t understand this comment. > > >> 6. >> 7. Document should cover the FAPM aspects for the Generic Metric and >> especially the Bandwidth metric. > > > Nor this one. > > >> 7. >> 8. The document introduces a new Generic Metric type called Bandwidth >> metric. I’ve been trying to follow some of the discussion related >> to this on the mailing list – about it being cumulative or not. I >> am perhaps somewhat confused by those discussions. The OSPF/ISIS >> SPT computation has always worked with cumulative link (and >> prefix) metrics. If the computation for the Generic Metric of this >> new type b/w is not going to be cumulative (I thought it is – but >> not very clear anymore), then the document needs to describe the >> computation algorithm. Is it then hop count based? Perhaps I am >> missing something very basic here and if so, please point me to >> the text in the draft. >> >> > > I’m sorry if this has been confusing. My understanding is that the > metric is cumulative. Others had other expectations. my expectation is to be cumulative as well. thanks, Peter > > When there are multiple links with the same bandwidth, and thus the same > metric, then the total path metric becomes (link metric) * (number of > links). > > Regards, > Tony >
- [Lsr] LSR WG Adoption Poll for "Flexible Algorith… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Jeff Tantsura
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Gyan Mishra
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Peter Psenak
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ron Bonica
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Lizhenbin
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Dongjie (Jimmy)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Peter Psenak
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Dongjie (Jimmy)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Dongjie (Jimmy)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Dongjie (Jimmy)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… peng.shaofu
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Dongjie (Jimmy)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Gyan Mishra
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Greg Mirsky
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Christian Hopps
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Anoop Ghanwani
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Christian Hopps
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Anoop Ghanwani
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Anoop Ghanwani
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Anoop Ghanwani
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Peter Psenak
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… gregory.mirsky
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Anoop Ghanwani
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… gregory.mirsky
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… gregory.mirsky
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… gregory.mirsky
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Anoop Ghanwani
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Aijun Wang
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Tony Li
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Peter Psenak
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Peter Psenak
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… bruno.decraene
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Peter Psenak
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… William Britto A J
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Rajesh M
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Acee Lindem (acee)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… tom petch
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Shraddha Hegde
- Re: [Lsr] LSR WG Adoption Poll for "Flexible Algo… Ketan Talaulikar (ketant)