detnet

Summary

This detnet session focused on the status of working group documents and discussions on raw, wireless, and miscellaneous topics. Presentations covered updates to the RAW architecture draft, requirements for reliable wireless industrial services, analysis of latency characteristics in mobile transmission, BFD extensions for remote defect indication, and request/reply mechanisms for detnet capability discovery. A key theme was incorporating wireless considerations into detnet architecture and functionality.

Key Discussion Points

RAW Architecture Draft Update: Torsten presented updates to the RAW architecture draft, focusing on a new figure illustrating RAW's role within the detnet architecture, reliability features, and the RAW API. Concerns were raised about inconsistencies within the document, particularly in definitions.
Requirements for Reliable Wireless Industrial Services: Carlos presented the draft on requirements for reliable wireless industrial services, emphasizing industrial applications and requirements. The discussion centered around making the document technology-agnostic (removing Wi-Fi focus) and ensuring consistent structure between sections.
Latency Characteristics of Mobile Transmission: Balaji presented an analysis of latency characteristics in mobile transmission, highlighting differences between wired and wireless detnet nodes, the impact of radio protocols, and the need for "wireless-friendly" latency algorithms. The impact of non-detnet traffic on latency and the QS architecture were discussed.
BFD Extension for Remote Defect Indication: A presentation from Huawei on BFD extensions for remote defect indication. Concerns were raised about the applicability of BFD in detnet, potential redundancy with active measurement protocols, and the need for a more generic mechanism. Multi-SLO environments in IPPM were suggested as a more relevant framework.
Request/Reply for detnet Capability Discovery: A presentation from Huawei on a mechanism for detnet capability discovery using ICMP. Alternative approaches using routing or existing mechanisms for capability discovery were suggested, along with clarification of the consumer of the information.
IPv6 Extension Header Considerations: Torres presented a perspective from 6man on minimizing code point exhaustion and exploring options for hop-by-hop vs. destination option headers. Discussions centered around a balance between scalability and control, including how much information needs to be provisioned.

Decisions and Action Items

Controller Plan Framework & Topology YANG Model: Susan to summarize the status and next steps for these documents on the mailing list for further discussion.
Authors to Provide Status Reports: The chairs announced a process change requiring status reports on all working group documents at each meeting, or via the mailing list at the internet-draft cutoff date. This is to facilitate discussion and encourage progress.
RAW Architecture Draft (Individual Contributors): Torsten to cross-check the document for consistency and proceed with updates as the working group is happy with the direction.
Requirements for Reliable Wireless Industrial Services (Authors): Revise the document to be technology-agnostic, removing the Wi-Fi focus, and ensure consistent structure. The working group should provide feedback and new revision needs to be made for last call.
BFT Extension for Remote Defect Indication (Authors): Consider multi-SLO environments in IPPM and general mechanisms, and submit a draft with updated information to the working group.
IPv6 Extension Header Considerations (Torres): The working group does not have agreement on Torres' proposed approach. Therefore, the working group suggests for Torres to ask in 6ban for general feedback on viability and what is not viable from 6man, so feedback can be brought back to the detnet working group for further review.

Next Steps

Authors to incorporate feedback and update drafts.
Continued discussion on the mailing list, particularly for documents nearing completion or requiring significant work.
Second detnet session later in the week to focus on queuing discussions and enhanced data plane topics.

Session Date/Time: 20 Mar 2024 23:30

detnet

Summary

The second detnet session at this IETF focused on enhanced data plane discussions. Key topics included updates on scaling requirements, a detailed review of the data plane taxonomy draft, and presentations on specific queuing mechanisms like EDF and Tiga-from, as well as C-SCORE and flow aggregation. The session aimed to characterize queuing proposals using the taxonomy, and explored challenges and solutions for achieving bounded latency and scalability in deterministic networks. There was also discussion on Wireless functionality.

Key Discussion Points

Scaling Requirements Update: Discussion on version 5 of the scaling requirements draft, focusing on enhancements to explanations, consideration of jitter bounds, end-to-end latency, and the complexity of queuing mechanism evaluation. Text was added regarding queuing solutions with multiple levels of detnet capabilities.
Data Plane Taxonomy Draft: A detailed overview of the taxonomy draft, which aims to categorize data plane solutions based on various criteria including performance characteristics, periodicity, network synchronization, traffic granularity, work conserving manner, target transmission time, and service order.
Taxonomy Intercorrelations: Exploration of the relationships between different taxonomies, such as the relationship between traffic granularity and the dominant factor for end-to-end latency bounds.
EDF Queuing Mechanism: Presentation and discussion on updates to the EDF queuing mechanism, including latency conversations, anti-mode, and a homomorphic topology example.
Tiga-from Queuing Mechanism: Updates on the Tiga-from queuing mechanism, covering time slot arrangements, BTM/BOM/FDM, run-time policy and delay jitter elimination, and taxonomic considerations.
C-SCORE Queuing Mechanism: Explanation and example of the C-SCORE queuing mechanisms and it's advantages over other CQF queuing proposals.
Flow Aggregation: Initial exploration of flow aggregation in enhanced detnet, identifying gaps and requirements related to scalability and fine-grained provisioning.
Buffer Size Considerations: A discussion about the constraints of buffer sizes in switches and routers in metropolitan networks, and how this can constrain solution options. Relatedly, several parties pointed out the trade-offs between buffer size and latency.
Reference Topologies: A lengthy discussion on reference topologies. The discussion focused on whether or not a reference topology was a use case. The determination was made that the taxonomy document should reference a topology, but is not a use case document.
Wireless requirements: Balaji highlighted the necessity of including aspects of wireless, special cases in queuing methods to accommodate wireless use cases.

Decisions and Action Items

Adoption of Taxonomy Draft: The chairs indicated intent to move the taxonomy draft towards adoption, pending further discussion on the mailing list.
Working Group Input on Topologies: Once adopted, the working group, not just the authors, will contribute to and refine reference topologies.
Review Yang Model for Aggregation: Alper (incomplete) and others need to review the existing data documents, especially about the free, flow aggregation part and in particular, the Yang document and the aggregation section there.

Next Steps

Mailing List Discussion: Continue discussions on the mailing list regarding topology, definitions, and justification.
Taxonomy Refinement: Authors to consider the inclusion of reference topologies and wireless aspects in the taxonomy draft and, particularly, the points raised in the discussion around reference topologies.
Flow Aggregation Analysis: Authors to analyze the existing data documents to determine gaps and clarifications for the flow aggregation section.