Hi Acee, Please check inline below for responses.
On Thu, May 23, 2024 at 1:58 AM Acee Lindem <acee.lin...@gmail.com> 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 <ketant.i...@gmail.com> 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 <acee.lin...@gmail.com> wrote: > >> >> >> On May 17, 2024, at 17:14, Acee Lindem <acee.lin...@gmail.com> wrote: >> >> Hi Ketan, Shraddha, >> >> On May 17, 2024, at 07:22, Ketan Talaulikar <ketant.i...@gmail.com> >> 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 >> 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 <shrad...@juniper.net> >> 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 <ketant.i...@gmail.com> >>> *Sent:* Saturday, April 27, 2024 11:44 AM >>> *To:* Shraddha Hegde <shrad...@juniper.net> >>> *Cc:* Acee Lindem <acee.lin...@gmail.com>; lsr <lsr@ietf.org>; >>> draft-ietf-lsr-flex-algo-bw-...@ietf.org >>> *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 <shrad...@juniper.net> >>> wrote: >>> >>> Hi Ketan, >>> >>> >>> >>> Thanks for reply. >>> >>> Pls see inline.. >>> >>> >>> >>> >>> >>> Juniper Business Use Only >>> >>> *From:* Ketan Talaulikar <ketant.i...@gmail.com> >>> *Sent:* Monday, April 8, 2024 2:25 PM >>> *To:* Shraddha Hegde <shrad...@juniper.net> >>> *Cc:* Acee Lindem <acee.lin...@gmail.com>; lsr <lsr@ietf.org>; >>> draft-ietf-lsr-flex-algo-bw-...@ietf.org >>> *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 <shrad...@juniper.net> >>> wrote: >>> >>> Hi Ketan, >>> >>> >>> >>> Thanks for the review and comments. >>> >>> Pls see inline for replies. >>> >>> >>> >>> >>> >>> Juniper Business Use Only >>> >>> *From:* Ketan Talaulikar <ketant.i...@gmail.com> >>> *Sent:* Thursday, March 21, 2024 10:07 PM >>> *To:* Acee Lindem <acee.lin...@gmail.com> >>> *Cc:* lsr <lsr@ietf.org>; draft-ietf-lsr-flex-algo-bw-...@ietf.org >>> *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 <acee.lin...@gmail.com> >>> 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 >>> Lsr@ietf.org >>> 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 -- lsr@ietf.org >> To unsubscribe send an email to lsr-le...@ietf.org >> >> >> _______________________________________________ >> Lsr mailing list -- lsr@ietf.org >> To unsubscribe send an email to lsr-le...@ietf.org >> >> >> _______________________________________________ > Lsr mailing list -- lsr@ietf.org > To unsubscribe send an email to lsr-le...@ietf.org > > >
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