Session Date/Time: 03 Nov 2025 22:00

DETNET Session Minutes - IETF 124

Chairs: Lou Berger (on-site), Janos Farkas (remote) Secretary: Schuller (remote) Date: [Implicit from IETF 124, e.g., March 2022]

Summary

The DETNET session at IETF 124 covered updates on existing working group documents, status of liaisons, and a series of presentations on proposed data plane solutions, flow aggregation, anomalous packet handling, multi-domain control plane frameworks, and SRv6 data plane integration. Key discussions revolved around the progress of solution drafts towards adoption, the need for enhanced interoperability descriptions, and foundational work for multi-domain DETNET. The chairs emphasized the importance of working group members reading all proposed solution documents to facilitate informed adoption decisions. A decision was made to propose the removal of inactive RAW-related milestones.

Key Discussion Points

Introduction and Logistics: Chairs provided updates on IETF Note Well, logistical tools, and document status. Three documents are in the RFC Editor's Queue (Wireless, Architecture, Control Plane Framework). Discussion on data plane solutions adoption is ongoing.
Inactive Documents and Milestones:
- The "RAW Industry Requirements" and "RAW Framework" documents were moved to a 'dead' state due to lack of contributions, but can be revived.
- Chairs noted upcoming milestones related to scaling work.
- Concerns were raised about inactive "RAW Framework" and "RAW OAM" milestones.
Liaisons:
- An action liaison from ITU-T SG13 (April) on which DETNET needs to respond; silence is not consent. Proposals for a response are requested.
- A liaison with other IETF WGs on IMT 2020 DC Camp is primarily handled by CCMP, but DETNET can contribute.
- A recent ITU-T SG13 liaison was for information only, noting consented and new work.
- A beneficial joint session with IEEE 802.1 TSN TG was held after the last IETF.
Data Plane Taxonomy (v4) Update (Gino):
- Proposed revisions for v5 to cover interoperability and compatibility:
  1. DETNET solutions with existing legacy networks (e.g., DiffServ).
  2. Heterogeneous DETNET solution domains (inter-solution compatibility). The working group's primary interest was clarified to be the latter (point 2).
- A new reference topology (3 cascaded domains) was proposed for interoperability evaluations.
- Preliminary thoughts on interoperability between rate-based and time-bounded solutions were presented, noting complexities when rate-based solutions precede time-bounded ones due to burst accumulation.
- A clear definition for "time-bound" was proposed.
Latency Guaranteed Stateless Fair Queuing (C-score) (Gino):
- Presented simulation results for interoperability with legacy Strict Priority (SP) DiffServ networks using a cascaded 3-domain topology.
- Results indicated C-score works seamlessly with SP networks (plug-and-play with resource reservation).
- Discussion on coexistence with time-bounded solutions, suggesting viability if time-bounded solutions are at edges with flow shaping.
Deadline-based Forwarding (EDF) (Shaofu):
- Updates included clarification on small SBI/large delay level and interoperability with SP.
- Categorization confirmed based on taxonomy document.
- Implementation details (ZTE LUTA) and interoperability test results with SP were provided.
Time-Sensitive Gate-Controlled Forwarding (TiGCF) (Shaofu):
- Updates on queue handling in TAS/TQF and improvements in TiGCF.
- Categorization confirmed, implementation in ZTE LUTA, and interoperability test with SP was presented.
TCQF and GLBF (Törless):
- Presented updates on two separate solutions: TCQF (periodic, class-based) and GLBF (non-periodic, class-based, academic-oriented).
- Flow interleaving was described as an optional component for both.
- A categorization overlap with EDF was noted, as GLBF and EDF both fall under Taxonomy category 6.5.
On-Time Forwarding with PIFOQ (Ian Cholu):
- Described support for multiple mechanisms (on-time traffic to PIFOQ, in-time traffic to FIFOQ).
- Categorized as flow-level, non-periodic bounded (category 4).
- FPGA implementation details and network test results demonstrating deterministic latency guarantees in a multi-service scenario were provided.
N-score (Ian Cholu):
- Presented a stateless, rate-based solution that does not require time synchronization.
- Categorized as flow-level rate-based left-bound (category 2).
- Mathematically proven with software-based simulations and plans for FPGA implementation.
Solution Poll Results (Chairs): Polls on readership and interest in adoption for the presented solutions showed low participation and no clear signal. Chairs stressed the need for WG members to read all documents to enable informed decision-making for adoption.
Flow Aggregation for Enhanced DETNET (Tianji):
- Presented as an informational draft.
- Motivation: Address scaling requirements in data plane (aggregated flow ID, multi-domain SLA) and control plane (N2A QS for aggregated flows).
- Proposed enhancements: Flow classification, identification, and coordination, with 5GS as an exemplary case.
Anomalous Packet Handling for DETNET (Jinjee):
- First presentation on handling anomalous forwarding behaviors caused by flow diversity, hardware limitations, high-priority packets, and resource conflicts.
- Proposed a policy-based framework with "squeezing" (temporary deferral while preserving scheduling info) and "degrading" (redirect to lower priority queue) policies.
- Feedback from chairs and participants suggested that many "anomalies" described might be normal network behaviors that should be accounted for in design rather than treated as anomalies.
PCE-based Control Plane Framework for Multi-Domain DETNET (Carlos):
- Proposed a functional framework building on the existing DETNET control plane, focusing on multi-domain challenges.
- Defined a DETNET domain based on PCE control (single PCE instance with complete topology visibility).
- Discussed two architectural approaches: Hierarchical PCE and Peer-to-Peer stitching.
- Highlighted considerations for multi-domain flow establishment (cumulative budgets, resource management, end-system awareness).
DETNET SRv6 Data Plane (Balázs Varga):
- Presented the merge of two SRv6-related drafts into a single Spring working group document, aligning with DETNET architecture.
- Major change: Redundancy-specific actions moved to SR policy, using a single redundancy SID.
- Defined new SR endpoint behaviors and policy head-end behaviors.
- An appendix illustrates complex scenarios involving SRv6 capable and non-capable nodes.

Decisions and Action Items

Decision: The chairs will send a message to the mailing list proposing the removal of the "RAW Framework" and "RAW OAM" milestones due to lack of progress and contributions.
Action Item (Gino): Update the Data Plane Taxonomy draft (v5) to include proposed revisions for interoperability, a new reference topology, and the definition of "time-bound". Distribute the updated draft to the working group mailing list for review and address categorization comments.
Action Item (Törless): Discuss the categorization overlap between GLBF and EDF (both identified in Taxonomy category 6.5) on the DETNET mailing list.
Action Item (Ian Cholu): Respond on the mailing list to questions regarding mathematical guarantees for "On-Time Forwarding with PIFOQ" and provide further description of evaluation and topology in the N-score document.
Action Item (Jinjee): Clarify the definition of "anomalies" in the "Anomalous Packet Handling for DETNET" draft and address the concerns raised about the squeezing and degrading policies on the mailing list.
Action Item (Working Group Members): Read all proposed data plane solution documents to provide informed feedback to the chairs to aid in adoption decisions.
Action Item (Chairs - Lou Berger & Janos Farkas):
- Discuss the outcome of the solution polls and formulate a plan for how to proceed with the adoption process for data plane solutions.
- Coordinate the DETNET SRv6 Data Plane work with the Spring Working Group.
Action Item (Lou Berger - Personal): Provide comments on the reference topology in the taxonomy document to elicit more information on how solutions handle competing traffic flows.
Action Item (Carlos Bernardo): Continue work on the PCE-based control plane framework for multi-domain DETNET, incorporating feedback and providing further updates.
Action Item (Balázs Varga): Present the DETNET SRv6 Data Plane updates at the upcoming Spring Working Group meeting.

Next Steps

Mailing List Discussions: Continued detailed technical discussions on all presented drafts, especially solution documents, flow aggregation, and anomalous packet handling, are encouraged.
Solution Adoption: The chairs will review the poll results and mailing list feedback to determine the next steps for adopting one or more data plane solution documents.
Multi-Domain Work: Further development of the multi-domain control plane framework is expected.
Cross-WG Coordination: Ongoing coordination with the Spring Working Group for SRv6-related work and with ITU-T SG13 for liaison responses.