Hi Shraddha, Thanks for sharing your text proposal. Will review and get back to you next week (post IETF).
Thanks, Ketan On Wed, Jul 24, 2024 at 9:20 PM Shraddha Hegde <[email protected]> wrote: > Hi Ketan, > > > > Here is the proposed text > > > > “Generic Metric is a link attribute appears in various TLVs as > > described in the beginning of this section. > > For Flex-algorithm purposes the use of Generic Metric sub-TLV is > > governed by the rules defined in sec 12 of <xref target ='RFC9350'/>. > > For applications such as RSVP-TE when used in packet networks and in > > GMPLS , Generic Metric is used from TE Link TLV of the OSPF TE LSA > <xref target ='RFC3630'/> > > as described in sec 4 of <xref target ='RFC9492'/>. > > For applications such as SR Policy <xref target ='RFC9652'/>, Generic > metric > > may be used from TE Link TLV of the OSPF TE LSA <xref target > ='RFC3630'/> > > as specified in sec 12.1 of <xref target ='RFC9492'/>” > > > > Let me know if that works for you. > > > > Rgds > > Shraddha > > > > > Juniper Business Use Only > From: Ketan Talaulikar <[email protected]> > *Sent:* Tuesday, July 23, 2024 11:29 PM > *To:* Acee Lindem <[email protected]> > *Cc:* Shraddha Hegde <[email protected]>; lsr <[email protected]>; > [email protected] > *Subject:* Re: [Lsr] Working Group Last Call for "Flexible Algorithms: > Bandwidth, Delay, Metrics and Constraints" - > draft-ietf-lsr-flex-algo-bw-con-07 > > > > *[External Email. Be cautious of content]* > > > > Hello Shraddha/Authors, > > > > Checking to see if we can conclude on the text to be added/updated to > cover the advertisement and usage for applications other than FlexAlgo like > RSVP-TE and SR Policy. > > > > Thanks, > > Ketan > > > > > > On Mon, May 27, 2024 at 8:27 AM Ketan Talaulikar <[email protected]> > wrote: > > Hi Acee, > > > > Please check inline below for responses. > > > > > > On Thu, May 23, 2024 at 1:58 AM Acee Lindem <[email protected]> wrote: > > Ketan, > > > > First of all, the have been early allocations for over almost 2 years now > and it isn’t very timely to object at the end of WG last call. However, I > think your concerns can easily be satisfied. > > > > KT> It is only at WGLC that the authors have indicated that the draft is > "complete" and therefore the WGLC seems the time for me to object that it > isn't complete? I agree that my concerns can be easily satisfied with > additional text - I've shared the suggestions for the same as well. > > > > > > On May 21, 2024, at 12:18, Ketan Talaulikar <[email protected]> wrote: > > > > Hi Acee, > > > > You seem to have misunderstood my concern. I am not asking for > specification of the RSVP-TE CSPF algorithm/computation using Generic > Metric. > > > > Let me clarify my objections. There are 3 ways in which Generic Metric can > be advertised for OSPFv2 as stated in this draft: > > > > 1) As a sub-TLV of the ASLA sub-TLV in the OSPFv2 Extended Link LSA : For > FlexAlgo usage this is the one and only one way to advertise Generic Metric > in OSPFv2 (note there is no L-bit in OSPF for ASLA). RFC 9492 (ASLA) allows > for this to be used for other applications beyond FlexAlgo. I would like > this draft to clarify if it is defining Generic Metric use for any > application other than FlexAlgo under ASLA - see further in my email. > > > > 2) As a top-level sub-TLV of the OSPFv2 Extended Link TLV in the OSPFv2 > Extended Link LSA : This document is making allocation in this namespace > but that is not an issue since the namespace is shared with ASLA. However, > the draft needs to clarify that it is not defining Generic Metric use for > any application when advertised this way as it is not used in base OSPF > route calculation. > > > > So, basically 1 and 2 are the same and equates to “Generic metric usage > for applications other than flex algorithm is out of scope. Future > documents may describe usage.” > > > > KT> Sure, that was the "easy" option that I had initially suggested. > However, Shraddha mentioned that she is aware of ongoing/existing > implementations and that is why I am instead suggesting that we add some > text to cover those other applications. I don't think it should be very > difficult to incorporate. > > > > > > > > 3) As a sub-TLV of the Link TLV in the OSPFv2 TE Opaque LSA : This > document is making an allocation in this namespace but not indicating any > application usage. If the intention is to use this advertisement for > RSVP-TE CSPF, then there is no issue since this is allowed per RFC 9492 > Section 12.3.4. However, the draft must explicitly state that this is the > only way to use it for RSVP-TE application. > > > > I’m looking at RFC 9492 Section 12.1 - why couldn’t the generic metric be > used for the other referenced applications - LFA and SR policy if usage is > described in a future document? Similar to above. > > > > KT> For SR Policy, it is certainly possible. For LFA, I am not sure at > this point other than within FlexAlgo. I would rather prefer that we add > small sections in the current draft that cover RSVP-TE and SR Policy at > least (as suggested). I can provide the text if the authors are OK with > this proposal. > > > > Thanks, > > Ketan > > > > > > Shraddha - can you provide these application scoping statements? > > > > Thanks, > > Acee > > > > > > > > Now, in addition to the above, there is the SR Policy CSPF computation > application (very similar to RSVP-TE) as well and this draft does not > clarify how Generic Metric is to be advertised for that application. Per > RFC9492, it should be as (1) and not as (2) or (3). > > > > Without this clarification, we are in for interop issues for all > applications other than FlexAlgo. > > > > Finally, the list of points that I shared earlier on this thread is not > about the actual CSPF computation algo, but more about the semantics of the > advertisement itself. > > > > I hope this clarifies why this draft is currently underspecified for > Generic Metric TLV usage for all applications other than FlexAlgo. > > > > Thanks, > > Ketan > > > > On Sat, May 18, 2024 at 4:19 AM Acee Lindem <[email protected]> wrote: > > > > > > On May 17, 2024, at 17:14, Acee Lindem <[email protected]> wrote: > > > > Hi Ketan, Shraddha, > > > > On May 17, 2024, at 07:22, Ketan Talaulikar <[email protected]> wrote: > > > > Hi Shraddha, > > > > Thanks for your response. I believe we now have only one open discussion > point and hence I am top posting my suggestions. > > > > If the authors wish to cover the Generic Metric TLV usage in TE Opaque > LSAs in this document then we will need more text/specification than "All > traditional TE applications like CSPF/RSVP make use of link-attributes from > TE-LSA." > > > > Since the new Generic Metric code point is in this registry - > https://www.iana.org/assignments/ospf-traffic-eng-tlvs/ospf-traffic-eng-tlvs.xhtml#subtlv2 > <https://urldefense.com/v3/__https:/www.iana.org/assignments/ospf-traffic-eng-tlvs/ospf-traffic-eng-tlvs.xhtml*subtlv2__;Iw!!NEt6yMaO-gk!Hw1velJ3JyEaSySQu0-3cLNruMadgKl7R6OJWSqwNbKOgV4EN8n8tJWmCtchQiveaITrqU17THmVGBa-qh-LrQ$> > I > don’t the issue with it being used for TE applications currently making use > of the TE Opaque LSA - we’re still using the OSPF TE Opaque LSA for > traditional TE. Right? > > > > > > > > Some suggestions which can be incorporated in a separate section that is > titled "Use of Generic Metric for RSVP-TE": > > - specify that Generic Metric TLV usage in TE Opaque LSAs is limited to > RSVP-TE use > > - specify the differences for use of bandwidth metric for RSVP-TE; I > assume it is a constant metric value itself since we don't have FAD to > determine the b/w metric > > - flex algo prunes links w/o the specific metric advertisements; will it > be the same for RSVP-TE CSPF? > > - cover backward compatibility aspects (e.g., what if the computation > needs to optimize on a particular metric and a set of routers/links don't > carry that metric value) > > > > I hope this gives an idea of the details necessary if this document is > attempting to cover use of generic metric for not just flex algo but other > applications. If there were any other applications/usage in mind, it would > be good to clarify that explicitly. We have many different LSAs in OSPF > resulting in potential interop issues if the specifications are not clear. > > > > Perhaps, it should be stated that usage will be specified in future > documents. This could included in the -13 version with Peter’s comments. > > > > On second thought, since RSVP signals the complete path, the TE path > computation typically has not be standardized and I don’t think this is > required. We can move forward with the -13 version with Peter’s comments. > > > > Thanks, > > Acee > > > > > > > > > > > > > > Thanks, > > Acee > > > > > > > > > > > > Thanks, > > Ketan > > > > > > On Thu, May 16, 2024 at 2:56 PM Shraddha Hegde <[email protected]> > wrote: > > Hi Ketan, > > > > Snipping to open points > > > > > > > > 2) This comment is specific to OSPF given the encoding differences it has > with ISIS. Section 2.2 allows for Generic Metric TLV to be used in too many > places without clear specification of what it is used for - this is a > potential pitfall for interop issues. RFC9492 provides helpful directions > for us here. > > a) This draft specifies FlexAlgo extensions, it is natural that Generic > Metric be advertised under ASLA TLV. No issues here. > > b) This draft does not specify anything about use of generic metric in > base OSPF and as a reminder there is nothing like L-bit in OSPF encoding. > Therefore, it does not make sense to advertise Generic Metric outside of > ASLA and under the OSPFv2 Extended Link TLV or OSPFv3 Router Link TLV. > > c) This draft does not specify anything about use of generic metric with > RSVP-TE/GMPLS. Therefore, it does not make sense to advertise Generic > Metric in the TE Opaque LSAs. > > We can have specific documents that introduce (b) or (c) when there is a > proper specification. > > <SH> Generic metric is a link attribute and can be used by other > applications apart from Flex-algo. > > I don’t see a reason to not take code-points under other applicable LSAs. > > > > KT> I disagree on this one. There is a reason why what is proposed in the > draft for ISIS is OK - due to the L-bit in ASLA, we need codepoints both > under ASLA and at the top level for FlexAlgo. There is no L-bit in OSPF and > therefore this does not apply. The code-points can be allocated when the > behavior is specified for those other LSAs and applications (beyond > FlexAlgo) in OSPF. We should not set the precedent for allocating > code-points for TLVs without any defined use or behavior. > > > > <SH2> Early code points are taken and implementations underway for other > applications. > > > > “Implementations MUST support sending and receiving generic metric > > sub-TLV in ASLA encodings as well as in the TLV 22/extended link > LSA/TE-LSAs. > > The usage of a generic metric by an individual application is subject to > the same > > rules that apply to other link attributes defined in respective standards.” > > > > The above text clarifies the use of generic metric by individual > application. > > > > KT2> I am not sure this is sufficient. Let us take an example. How is the > Generic Metric TLV received in OSPFv2 TE Opaque LSA handled and what is it > used for? > > > > <SH3> The text in the draft says the applications that make use of link > attributes from TE LSA will also use generic metric from TE-LSA. All > traditional TE applications like CSPF/RSVP make use of link-attributes from > TE-LSA. I don’t see the need to say anything beyond what has already been > said in the draft. > > > > The Min Unidirectional Link Delay as advertised by *sub-sub-TLV 12* of > ASLA sub-TLV [RFC8920 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*RFC8920__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmun5uDKc7A$>], > MUST be compared against the Maximum delay advertised in the FAEMD sub-TLV. > > <SH> changed to “The Unidirectional Link Delay as advertised by *sub-sub-TLV > 12”* > > > > KT> Perhaps my comment was not clear. The following text would be more > accurate: > > > > The Min Delay value advertised via the Min/Max Unidirectional Link Delay > sub-TLV [RFC7471] of the ASLA sub-TLV [RFC8920 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*RFC8920__;Iw!!NEt6yMaO-gk!HoQCxz15c5OoUVXjpmPpCU0N94Ex0cMuET6hFT8l6FE_kNkB58lpI-LSmXBUJvY4IdViL2mzTjVwvp4nyibk3A$>], > MUST be compared against the Maximum delay advertised in the FAEMD sub-TLV. > > <SH2> I think there is a misunderstanding here. You are proposing to use > sub-tlv 13 where as the text in the draft clearly proposes to use sub-tlv > 12. This probably justifies why it is important to specify sub-tlv number > > And not just name. > > > > KT2> Well, that is what I am also trying to point out ... that the draft > is wrong :-) The one to use is 13 - please check below and let me know if > I am missing something. I also urge you to stick to using OSPF conventions > of using TLV names as opposed to the ISIS convention of using TLV numbers. > > > > Refer: https://www.rfc-editor.org/rfc/rfc9350.html#section-5.2 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc9350.html*section-5.2__;Iw!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvQO78JKxQ$> > ... > look for IGP metric type 1 > > And then: https://www.rfc-editor.org/rfc/rfc7471#section-4.2 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc7471*section-4.2__;Iw!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvSIQb9eeQ$> > and https://www.rfc-editor.org/rfc/rfc8920.html#section-14.1 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc8920.html*section-14.1__;Iw!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvRWLiM03A$> > > 12 > > Unidirectional Link Delay > > Y > > [RFC9492 > <https://urldefense.com/v3/__https:/www.iana.org/go/rfc9492__;!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvT7cfK2pA$> > ] > > 13 > > Min/Max Unidirectional Link Delay > > Y > > [RFC9492 > <https://urldefense.com/v3/__https:/www.iana.org/go/rfc9492__;!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvT7cfK2pA$> > ] > > > > <SH3> Ok I got it. Will fix in -12 version > > > > > > > > 7) Regarding > https://www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html#section-6 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*section-6__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmumnzxX7UA$>, > it seems like we want to retain a numbering ordering of rules/sequence for > flex-algo as extension documents are introduced. Am I correct? If so, then > this document should formally "update" RFC9350 since it is changing the > "set of rules/sequence" for FlexAlgo computations. Further such extensions > will also need to keep updating the base spec similarly. I would suggest > that a full set of rules that is a union of what is in RFC9350 and rules > added by this draft are maintained in an Appendix section. Other documents > in the future can similarly maintain the latest set of rules. > > <SH> This draft is adding 2 new rules at the end of existing rules. Its > not modifying or changing the order. > > I don’t see what value it is going to add by repeating the set of rules in > Appendix. > > > > KT> What happens when another FlexAlgo document adds more rules? What > happens when some FlexAlgo document wants to insert rules in the middle of > existing ones instead of appending at the end? My point is that if there is > a desire to establish a "live" set of rules in specific orders, then we > need to leave a trail of document "updates" on the base FlexAlgo that one > can refer to know how these "live set of rules" are getting "updated" by > this and future documents. I am thinking of this on lines similar to an > update for an FSM. > > <SH2> It’s a matter of choice. For ex RFC 8029 > > Has so many updates to the Rules but each update only lists > the changes. > > > > KT2> I am not sure I follow and it would help if you can perhaps give an > example. > > > > I am fine with whatever WG decides to do. > > I want to hear if anyone in WG has an opinion on adding > Appendix. > > > > KT2> Sure. My point is that this seems like an ordered set of rules that > are being updated by multiple documents (more to come). How does one keep > track of the "current" set of rules without some trail or each new(er) > document capturing the "latest" set? > > <SH3> I don’t see any other opinions on mailing list. Will add appendix in > -12 with full set of rules. > > > > Rgds > > Shraddha > > > > > > Juniper Business Use Only > > *From:* Ketan Talaulikar <[email protected]> > *Sent:* Saturday, April 27, 2024 11:44 AM > *To:* Shraddha Hegde <[email protected]> > *Cc:* Acee Lindem <[email protected]>; lsr <[email protected]>; > [email protected] > *Subject:* Re: [Lsr] Working Group Last Call for "Flexible Algorithms: > Bandwidth, Delay, Metrics and Constraints" - > draft-ietf-lsr-flex-algo-bw-con-07 > > > > *[External Email. Be cautious of content]* > > > > Hi Shraddha, > > > > Please check inline below with KT2. > > > > On Mon, Apr 15, 2024 at 12:16 PM Shraddha Hegde <[email protected]> > wrote: > > Hi Ketan, > > > > Thanks for reply. > > Pls see inline.. > > > > > > Juniper Business Use Only > > *From:* Ketan Talaulikar <[email protected]> > *Sent:* Monday, April 8, 2024 2:25 PM > *To:* Shraddha Hegde <[email protected]> > *Cc:* Acee Lindem <[email protected]>; lsr <[email protected]>; > [email protected] > *Subject:* Re: [Lsr] Working Group Last Call for "Flexible Algorithms: > Bandwidth, Delay, Metrics and Constraints" - > draft-ietf-lsr-flex-algo-bw-con-07 > > > > *[External Email. Be cautious of content]* > > > > Hi Shraddha, > > > > Thanks for your responses. Please check inline below for clarifications > with KT. > > > > > > On Thu, Apr 4, 2024 at 9:49 AM Shraddha Hegde <[email protected]> > wrote: > > Hi Ketan, > > > > Thanks for the review and comments. > > Pls see inline for replies. > > > > > > Juniper Business Use Only > > *From:* Ketan Talaulikar <[email protected]> > *Sent:* Thursday, March 21, 2024 10:07 PM > *To:* Acee Lindem <[email protected]> > *Cc:* lsr <[email protected]>; [email protected] > *Subject:* Re: [Lsr] Working Group Last Call for "Flexible Algorithms: > Bandwidth, Delay, Metrics and Constraints" - > draft-ietf-lsr-flex-algo-bw-con-07 > > > > *[External Email. Be cautious of content]* > > > > Hi All, > > > > I have reviewed this document and believe it needs some further work > before publication. > > > > I am sharing my comments below: > > > > 1) There is the following text in sec 2.1 and 2.2 for Generic Metric. > > > > A metric value of 0xFFFFFF is considered as maximum link metric and a link > having this metric value MUST NOT be used during Flex-algorithm > calculations [RFC9350 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*RFC9350__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmuk-veyTXw$>]. > The link with maximum generic metric value is not available for the use of > Flexible Algorithms but is availble for other use cases. > > > > I believe the FlexAlgo reference here is to > https://www.rfc-editor.org/rfc/rfc9350.html#name-max-metric-consideration > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc9350.html*name-max-metric-consideration__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmumv0_0Zeg$> > > > > > But the above text does not align with the RFC9350. If a link is to be > made unavailable for FlexAlgos operating with a specific Generic Metric, > then the way to do that is to omit that specific Generic Metric TLV from > the ASLA for flex-algo application. The same would apply for other > applications - just omit the metric. Why do we need a special > MAX-LINK-METRIC value for generic metric given that it is a new thing we > are introducing? > > > > <SH> I see what you are saying. Text is updated as below for ISIS and > similar for OSPF. > > “A metric value of > > 0xFFFFFF is considered as maximum link metric and a link having > > this metric value MUST be used during Flex-algorithm calculations > > as a last resort link as described in sec 15.3 of RFC[9350] > > > > KT> Thanks - that works. Perhaps also clarify that to make the link > unusable by FlexAlgo using that generic metric, the advertisement of the > particular generic metric can be skipped. > > <SH2> ok > > > > > > 2) This comment is specific to OSPF given the encoding differences it has > with ISIS. Section 2.2 allows for Generic Metric TLV to be used in too many > places without clear specification of what it is used for - this is a > potential pitfall for interop issues. RFC9492 provides helpful directions > for us here. > > a) This draft specifies FlexAlgo extensions, it is natural that Generic > Metric be advertised under ASLA TLV. No issues here. > > b) This draft does not specify anything about use of generic metric in > base OSPF and as a reminder there is nothing like L-bit in OSPF encoding. > Therefore, it does not make sense to advertise Generic Metric outside of > ASLA and under the OSPFv2 Extended Link TLV or OSPFv3 Router Link TLV. > > c) This draft does not specify anything about use of generic metric with > RSVP-TE/GMPLS. Therefore, it does not make sense to advertise Generic > Metric in the TE Opaque LSAs. > > We can have specific documents that introduce (b) or (c) when there is a > proper specification. > > <SH> Generic metric is a link attribute and can be used by other > applications apart from Flex-algo. > > I don’t see a reason to not take code-points under other applicable LSAs. > > > > KT> I disagree on this one. There is a reason why what is proposed in the > draft for ISIS is OK - due to the L-bit in ASLA, we need codepoints both > under ASLA and at the top level for FlexAlgo. There is no L-bit in OSPF and > therefore this does not apply. The code-points can be allocated when the > behavior is specified for those other LSAs and applications (beyond > FlexAlgo) in OSPF. We should not set the precedent for allocating > code-points for TLVs without any defined use or behavior. > > > > <SH2> Early code points are taken and implementations underway for other > applications. > > > > “Implementations MUST support sending and receiving generic metric > > sub-TLV in ASLA encodings as well as in the TLV 22/extended link > LSA/TE-LSAs. > > The usage of a generic metric by an individual application is subject to > the same > > rules that apply to other link attributes defined in respective standards.” > > > > The above text clarifies the use of generic metric by individual > application. > > > > KT2> I am not sure this is sufficient. Let us take an example. How is the > Generic Metric TLV received in OSPFv2 TE Opaque LSA handled and what is it > used for? > > > > > > 3) Please introduce a reserved field to pad the OSPF FAEMD sub-TLV to a 4 > octet boundary as is the convention in OSPF - > https://www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html#section-3.2.2 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*section-3.2.2__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmunYcymQgw$> > > <SH> OK > > > > KT> Thanks. > > > > > > 4) In section 3.2.2 there is the following text for OSPF. Could you please > use the TLV/sub-TLV name? OSPF folks are not good at remembering numbers ;-) > > > > The Min Unidirectional Link Delay as advertised by *sub-sub-TLV 12* of > ASLA sub-TLV [RFC8920 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*RFC8920__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmun5uDKc7A$>], > MUST be compared against the Maximum delay advertised in the FAEMD sub-TLV. > > <SH> changed to “The Unidirectional Link Delay as advertised by *sub-sub-TLV > 12”* > > > > KT> Perhaps my comment was not clear. The following text would be more > accurate: > > > > The Min Delay value advertised via the Min/Max Unidirectional Link Delay > sub-TLV [RFC7471] of the ASLA sub-TLV [RFC8920 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*RFC8920__;Iw!!NEt6yMaO-gk!HoQCxz15c5OoUVXjpmPpCU0N94Ex0cMuET6hFT8l6FE_kNkB58lpI-LSmXBUJvY4IdViL2mzTjVwvp4nyibk3A$>], > MUST be compared against the Maximum delay advertised in the FAEMD sub-TLV. > > <SH2> I think there is a misunderstanding here. You are proposing to use > sub-tlv 13 where as the text in the draft clearly proposes to use sub-tlv > 12. This probably justifies why it is important to specify sub-tlv number > > And not just name. > > > > KT2> Well, that is what I am also trying to point out ... that the draft > is wrong :-) The one to use is 13 - please check below and let me know if > I am missing something. I also urge you to stick to using OSPF conventions > of using TLV names as opposed to the ISIS convention of using TLV numbers. > > > > Refer: https://www.rfc-editor.org/rfc/rfc9350.html#section-5.2 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc9350.html*section-5.2__;Iw!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvQO78JKxQ$> > ... > look for IGP metric type 1 > > And then: https://www.rfc-editor.org/rfc/rfc7471#section-4.2 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc7471*section-4.2__;Iw!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvSIQb9eeQ$> > and https://www.rfc-editor.org/rfc/rfc8920.html#section-14.1 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc8920.html*section-14.1__;Iw!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvRWLiM03A$> > > 12 > > Unidirectional Link Delay > > Y > > [RFC9492 > <https://urldefense.com/v3/__https:/www.iana.org/go/rfc9492__;!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvT7cfK2pA$> > ] > > 13 > > Min/Max Unidirectional Link Delay > > Y > > [RFC9492 > <https://urldefense.com/v3/__https:/www.iana.org/go/rfc9492__;!!NEt6yMaO-gk!CCtWq3oQk0cXbjdWmHoJomutLcmgPIHyX5LjNSahUulgW61QgLgqXr_Kj74WrmzBmvkbwwnzm_SiyvT7cfK2pA$> > ] > > > > > > > > 5) Do we want to call out that the reference bandwidth approach requires a > router to compute and maintain a per link per algo bandwidth metric for > every link in that algo topology. It may not be very obvious to some. > > <SH> updated as below > > “Advertising > > the reference bandwidth in the FAD constraints allows the metric > > computation to be done on every node for each link. > > The metric is computed using reference bandwidth and the advertised > link bandwidth. > > Centralized control of this > > reference bandwidth simplifies management in the case that the > > reference bandwidth changes” > > > > KT> The above text is not really needed IMHO. My point was more about the > implementation detail - for the flexalgo computation, we need to maintain > this info on a per link per algo topology basis in the link-state data > store used for path computation. I will leave it to the authors if this is > needed or is obviously clear to implementers. > > <SH2> I don’t see the need to add implementation specific details. > > > > KT2> OK - I leave it to you. > > > > > > 6) There are a lot of procedures which are common to both OSPF and ISIS > and are repeated in each section instead of a common section. It would be > easier (and avoid errors) if there was some consolidation. > https://www.rfc-editor.org/rfc/rfc9350.html#section-5 > <https://urldefense.com/v3/__https:/www.rfc-editor.org/rfc/rfc9350.html*section-5__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmumpoQRYAA$> > provides > a good reference for such an organization of text. > > <SH> There is repetition in some cases but its not much so it seems to me > leaving it as is for clarity may be better. > > > > KT> This is an editorial comment so I leave it to the authors. My concern > is that great care/diligence is required through the rest of the > publication process to ensure that when anything is changed or updated for > one IGP, it is done appropriately for the other as well - it may be > copy/paste case when the change is IGP agnostic but may need careful > consideration when related to the specific IGP mechanics. > > > > > > 7) Regarding > https://www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html#section-6 > <https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-ietf-lsr-flex-algo-bw-con-08.html*section-6__;Iw!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmumnzxX7UA$>, > it seems like we want to retain a numbering ordering of rules/sequence for > flex-algo as extension documents are introduced. Am I correct? If so, then > this document should formally "update" RFC9350 since it is changing the > "set of rules/sequence" for FlexAlgo computations. Further such extensions > will also need to keep updating the base spec similarly. I would suggest > that a full set of rules that is a union of what is in RFC9350 and rules > added by this draft are maintained in an Appendix section. Other documents > in the future can similarly maintain the latest set of rules. > > <SH> This draft is adding 2 new rules at the end of existing rules. Its > not modifying or changing the order. > > I don’t see what value it is going to add by repeating the set of rules in > Appendix. > > > > KT> What happens when another FlexAlgo document adds more rules? What > happens when some FlexAlgo document wants to insert rules in the middle of > existing ones instead of appending at the end? My point is that if there is > a desire to establish a "live" set of rules in specific orders, then we > need to leave a trail of document "updates" on the base FlexAlgo that one > can refer to know how these "live set of rules" are getting "updated" by > this and future documents. I am thinking of this on lines similar to an > update for an FSM. > > <SH2> It’s a matter of choice. For ex RFC 8029 > > Has so many updates to the Rules but each update only lists > the changes. > > > > KT2> I am not sure I follow and it would help if you can perhaps give an > example. > > > > I am fine with whatever WG decides to do. > > I want to hear if anyone in WG has an opinion on adding > Appendix. > > > > KT2> Sure. My point is that this seems like an ordered set of rules that > are being updated by multiple documents (more to come). How does one keep > track of the "current" set of rules without some trail or each new(er) > document capturing the "latest" set? > > > > Thanks, > > Ketan > > > > > > Thanks, > > Ketan > > > > > > > > 8) Please fix idnits warnings - some are related to obsolete references > while others are related to formatting. There are also some > spelling/grammar errors. > > <SH> ok > > > > Thanks, > > Ketan > > > > > > On Tue, Feb 20, 2024 at 3:56 AM Acee Lindem <[email protected]> wrote: > > > This starts the Working Group Last call for > draft-ietf-lsr-flex-algo-bw-con-07. At least some of the flex algorithm > enhancements described in the document have been implemented. > > Please send your support or objection to this before March 5th, 2024. > > Thanks, > Acee > _______________________________________________ > Lsr mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/lsr > <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/lsr__;!!NEt6yMaO-gk!DwOojW2YZ48IROz9qMyyh7uKj3rYC-09avEhFQtcPkvxJ5mKF5Cyy6qSVvDJ89s9DmAUVwsT_pgfmukG-EHJRw$> > > _______________________________________________ > Lsr mailing list -- [email protected] > To unsubscribe send an email to [email protected] > > > > _______________________________________________ > Lsr mailing list -- [email protected] > To unsubscribe send an email to [email protected] > > > > _______________________________________________ > Lsr mailing list -- [email protected] > To unsubscribe send an email to [email protected] > > > >
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