Hi Dhruv, I've also posted my review of the document from the POV of consistency with SR Policy Arch and BGP SR Policy SAFI documents
https://mailarchive.ietf.org/arch/msg/pce/xExbrHXRsC66fGUdy5wtvQlbXc4/ I hope these help improve the document by providing a better overall context of these very important PCEP extensions for SR. Thanks, Ketan On Sat, Apr 6, 2024 at 7:46 PM Dhruv Dhody <d...@dhruvdhody.com> wrote: > Hi Mike, Authors, > > Please make a new version of the I-D where you handle the following items. > We can then send the I-D to the IESG. > > (1) Please handle Ketan's concern and add the IANA note as he suggested - > https://mailarchive.ietf.org/arch/msg/pce/ZaYof63GNYdplFUOLo6G6hJlx3c/ > > (2) A few comments/query got missed, please update or respond if no > changes are needed... > > - Section 5.2, I am unsure about the interaction between the unsetting of > P-flag (PCEP speaker does not support the TLV) and the default value (128 > when the TLV is not present). Isn't it a bit weird? > - Section 5.4, Should Oper/Config get a registry for ease of adding new > flags in future? > > (3) Some new comments on checking the diff > > - abstract, s/[RFC8231]/RFC 8231/ (no references in abstract) > - s/ANY/any/ > - RFC 7525 is obsolete by RFC 9325, please update! > > (4) I am working on the shepherd writeup - > https://notes.ietf.org/HziLkaoxS6iYoQ3sOcwk-A?view ; will update in the > datatracker once you post a new version handling these. > > Thanks! > Dhruv > > On Mon, Mar 18, 2024 at 7:40 AM Mike Koldychev <mkold...@proton.me> wrote: > >> Hi Dhruv, >> >> I've incorporated your changes and all the other comments that I have >> received so far. Hopefully I didn't miss anything. Version 15 is uploaded. >> Thanks a lot for your comments and updates! >> >> Thanks, >> Mike. >> >> On Saturday, March 9th, 2024 at 8:23 AM, Dhruv Dhody <d...@dhruvdhody.com> >> wrote: >> >> Hi Authors, >> >> I have finished the shepherd review of >> draft-ietf-pce-segment-routing-policy-cp-14. Please handle these comments >> before we ship this I-D to IESG. >> >> ## Major >> - Section 5.6, you need to add update: RFC 8231 in the draft metadata. >> This should also be captured in the abstract. The prefered way is to >> clearly identify the text in RFC8231 that is changing with "OLD:" and >> "NEW:" format! >> - Section 8, Security considerations need to also cover the non-SRPA TLVs >> which are not considered in the current text. >> >> ## Query >> - Section 4.1, >> ```` >> If the PCC receives a >> PCInit message with the Association Source set not to the headend IP >> but to some globally unique IP address that the headend owns, then >> the PCC SHOULD accept the PCInit message and create the SRPA with the >> Association Source that was sent in the PCInit message. >> ```` >> What is the purpose of this text? PCC should use the source as set by the >> PCE - isn't it given? Am I missing something? Boris also pointed this out >> in his review. >> >> >> ## Minor >> - Abstract is not very useful for a non-expert. Maybe change something >> like - >> ```` >> OLD: >> A Segment Routing (SR) Policy is a non-empty set of SR Candidate >> Paths, which share the same <headend, color, endpoint> tuple. SR >> Policy is modeled in PCEP as an Association of one or more SR >> Candidate Paths. PCEP extensions are defined to signal additional >> attributes of an SR Policy. The mechanism is applicable to all SR >> forwarding planes (MPLS, SRv6, etc.). >> NEW: >> Segment Routing (SR) allows a node to steer a packet flow along any >> path. SR Policy is an ordered list of segments (i.e., >> instructions) that represent a source-routed policy. Packet flows >> are steered into an SR Policy on a node where it is instantiated >> called a headend node. An SR Policy is made of one or more candidate >> paths. >> >> This document specifies Path Computation Element Communication >> Protocol (PCEP) extension to associate candidate paths of the SR >> Policy. It applies equally to the SR-MPLS and Segment Routing over >> IPv6 (SRv6) instantiations of segment routing. >> END >> ```` >> - Similarly I find Introduction to be very light on details. Consider >> adding text by looking through recently published RFCs for instance. >> - Terminology: >> ``` >> OLD: >> SRPA: SR Policy Association. PCEP ASSOCATION that describes the SR >> Policy. Depending on discussion context, it refers to a PCEP >> object or to a group of LSPs that belong to the Association. >> NEW: >> SRPA: SR Policy Association. A new association type 'SR Policy >> Association' is used to group candidate paths belonging to the SR >> Policy. Depending on discussion context, it can refer to the PCEP >> ASSOCIATION object of SR Policy type or to a group of LSPs that >> belong to the association. >> END >> ``` >> - Section 4, please add this text at the start - >> ```` >> As per [RFC8697], LSPs are associated with other LSPs with which they >> interact by adding them to a common association group. As described >> in [RFC8697], the association group is uniquely identified by the >> combination of the following fields in the ASSOCIATION object: >> Association Type, Association ID, Association Source, and (if >> present) Global Association Source or Extended Association ID, >> referred to as Association Parameters. >> ```` >> - Section 4.2, since none of the TLV are multi-instance. Can we simplify >> this text - >> ```` >> OLD: >> Unless specifically stated otherwise, the TLVs listed in the >> following sub-sections are assumed to be single instance. Meaning, >> only one instance of the TLV SHOULD be present in the object and only >> the first instance of the TLV SHOULD be interpreted and subsequent >> instances SHOULD be ignored. >> NEW: >> This document specifies four new TLVs to be carried in the SRPA object. >> Only one TLV instance of each type can be carried, and only the first >> occurrence is processed. Any others MUST be ignored. >> ```` >> Also applicable to section 5! >> - Section 4.2.2, consider changing the SHOULD to MUST in this section. I >> could not think of a justification for SHOULD here! >> - Section 5.1, >> - please also state what happens if the TLVs are used without the >> exchange of SRPOLICY-CAPABILITY TLV or the corresponding bit is unset. >> Without it, what is the use of adding this TLV? >> - Consider updating the description such as "P-flag: If set to '1' by a >> PCEP speaker, the P flag indicates that the PCEP speaker supports the >> handling of COMPUTATION-PRIORITY TLV for the SR Policy." >> - please add "Unassigned bits MUST be set to '0' on transmission and MUST >> be ignored on receipt." >> - Section 5.2, I am unsure about the interaction between the unsetting of >> P-flag (PCEP speaker does not support the TLV) and the default value (128 >> when the TLV is not present). Isn't it a bit weird? >> - Section 5.3, should the use of this TLV be limited to SR-MPLS? Also can >> ENLP value be converted into a registery maintained at >> https://www.iana.org/assignments/segment-routing/segment-routing.xhtml >> which can be referred by both PCE and BGP? >> - Section 5.4, please add "The unassigned bits in the Flag octet MUST be >> set to zero upon transmission and MUST be ignored upon receipt." Should >> "Invalidation Reasons Flags" get a registry for ease of adding new flags in >> future? In general, can the text in this section be tightened a little bit? >> Examples - be explicit on who is sending and who is receiving for instance. >> Also, consider adding a more detailed example to show the usage of the >> flags better alongside PCEP message exchange. >> - Section 5.5, please add normative reference to >> draft-ietf-pce-binding-label-sid >> - Section 6.5, are you refereing to the registry at >> https://www.iana.org/assignments/segment-routing/segment-routing.xhtml, >> in which case it is called "Segment Routing" and not "Segment Routing >> Parameters". Also better to call the new registry being added as >> subregistry. >> - Section 10.2, please make RFC 8253 and RFC 7525 as normative >> references. >> >> ## Nits >> - Expand PCEP and SR in the title >> - Expand PCEP, SRv6 in the abstract >> - Expand MBZ on first use. It is also better to state that the field is >> ignored on receipt >> - Section 4.2.2, add reference to RFC 9256 for Discriminator, as you have >> done for other fields >> - Section 4.2.4, add reference to RFC 9356 for Preference >> - s/there needs to be a separate capability negotiation/a separate >> capability negotiation is useful/ >> - Expand on first use OAM/PM/BFD >> - Section 6, please update the text in subsections where the number of >> assignments in tables do not match the introductory text. >> >> I am also attaching the updated xml that could be a starting point for >> you to work on -15 version. >> >> Thanks! >> Dhruv >> >> >>
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