Thank you Carlos for the OpsDir review and your suggestions. Please see replies inline with <RG>...
On Tue, Nov 11, 2025 at 10:40 AM Carlos Pignataro via Datatracker < [email protected]> wrote: > Document: draft-ietf-pce-sr-bidir-path > Title: Path Computation Element Communication Protocol (PCEP) Extensions > for > Associated Bidirectional Segment Routing (SR) Paths Reviewer: Carlos > Pignataro > Review result: Has Issues > > Document: PCEP Extensions for Associated Bidirectional SR Paths > Filename: draft-ietf-pce-sr-bidir-path-16 > Reviewer: Carlos Pignataro > Intended Status: Standards Track > Date: November 2025 > Reviewer: Carlos Pignataro > > This is a well-written, technically mature document, consistent (even > mirror-ish) with the RSVP-TE precedent in [RFC 9059]. Clear alignment with > existing PCEP association mechanisms and SR architecture. No fundamental > operational blockers identified. > <RG> Thank you. > > >From an OpsDir perspective, I found a areas potentially lacking in > coverage: > > 1. Operational impact: The draft says “Mechanisms defined … do not imply > new > operational requirements” (not verbatim, but spread across sections 7.1 > through > 7.5), but introducing bidirectional SR associations does impact controller > behavior, inventory/state correlation, and troubleshooting. > > Consider adding a short note under §7.6 recognizing state correlation > complexity and diagnostic tooling implications (e.g., mapping PLSP-ID > pairs and > verifying forward/reverse coherence). > <RG> How about following? 7.6. Impact On Network Operations Mechanisms defined in [RFC5440], [RFC8231], and [RFC8408] also apply to PCEP extensions defined in this document. Associating forward and reverse SR Paths to form a bidirectional SR Path requires an operator to ensure that the correct LSP associations are employed on both sides of the SR Paths. New tools such as directed BFD [RFC9612] and Performance Measurement (PM) [RFC9503] can be used to verify the correct operation of a bidirectional SR Path. > > 2. Interoperability / Backward Compatibility: Early allocation of “8” is > great, > what are the PCE mechanisms for devices not supporting it? > > Consider an explicit mention of graceful ignore / PCErr. > <RG> This is already covered in RFC 9059. Not sure if we should repeat it here. https://datatracker.ietf.org/doc/rfc9059/ If a PCE speaker receives an LSP with a Bidirectional LSP Association Type that it does not support, the PCE speaker MUST send PCErr with Error-Type = 26 (Association Error) and Error-value = 1 (Association Type is not supported). > > 3. Clarify mismatches: Error-Type = 26 and Error-value = 16 are already > used > for RSVP-TE vs. SR-MPLS in rfc9059. Do you need to clarify that this is > also > the same used for SR-MPLS (RFC 8408) vs. SR-v6 (RFC 9256)? > <RG> How about following? [RFC9059] in Section 5.7, defines a PCErr message for the Path Setup Type (PST) of '0: Path is set up using the RSVP-TE signaling protocol' [RFC8408]. The PST for SR Path is set to '1: Traffic- engineering path is set up using Segment Routing' [RFC8664] or '3: Traffic engineering path is set up using SRv6' [RFC9603]. If a PCEP speaker receives an unsupported PST value for the 'Double-Sided Bidirectional with Reverse LSP Association', the PCE speaker MUST return a PCErr message with Error-Type = 26 (Association Error) and Error-value = '16: Path Setup Type not supported' [RFC9059]. > > 4. Manageability / YANG – for the YANG experts, is the text in §7.2 really > enough or more description on how to model needed? > <RG> Added a sentence as following: 7.2. Information and Data Models [RFC7420] describes the PCEP MIB; there are no new MIB Objects defined for LSP associations. The PCEP YANG module [RFC9826] defines a data model for *LSP associations. * H*owever, it does not include reverse LSP information.* > > I hope these are useful and clear. > <RG> Yes, they are. Many thanks. Rakesh (for authors) > > Thanks, and very best, > > Carlos Pignataro. > > > > _______________________________________________ > Pce mailing list -- [email protected] > To unsubscribe send an email to [email protected] >
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