detnet

Summary

This detnet session covered several draft updates and proposals related to deterministic networking. Key topics included enhanced data plane considerations, queuing mechanisms, flow interleaving, and application interfaces. The group discussed requirements for scaling deterministic networks, evaluated TSN mechanisms, and explored various queuing and scheduling approaches. Several presenters sought feedback and discussed future steps for their drafts. The session concluded with a poll indicating continued interest in discussing application interfaces for deterministic networks.

Key Discussion Points

Enhanced Detnet Data Plane: David Dial provided an update on open working meetings focusing on the enhanced data plane. Discussions centered on requirements, draft content, and evaluations of TSN mechanisms. The importance of in-depth presentations on queuing and scheduling mechanisms was highlighted.
Scaling Requirements Draft: Peng updated the group on the scaling requirements draft, including changes to bandwidth utilization, flow scalability, and handling flow fluctuations. The need for clarity in defining "flow fluctuation" was raised.
TZQF Draft: Yidro presented an update on the TZQF draft, focusing on merging different approaches and decoupling forwarding specifications from encapsulations. A demonstration of the technology over a large-scale network was shown.
EDF Scheduling: Shafu introduced updates to a proposal for Earliest Deadline First (EDF) scheduling, emphasizing rate control and sorted queues. Concerns were raised about the novelty of the approach compared to existing literature and the validity of latency calculations.
Time-Slotted Queuing: A presentation on time-slotted queuing explored resource reservation and conflict avoidance. Concerns were voiced about the practicality of Priority Input First Output (PIFO) queuing.
GLBF (Guaranteed Latency with Buffering Forwarding): Torlas introduced GLBF as a TSN-ATS solution with dampers instead of interleaf regulators. GLBF aims to achieve on-time delivery without per-hop state management.
Latency Guarantee with Stateless Fair Queuing: A new draft on Latency Guarantee with Stateless Fair Queuing was presented and the concept of ideal flow isolation was explained. There were discussions on entrance nodes needing to keep flow state.
Clock Referencing Plane: A proposal of new package queuing and compressing method.
Flow Interleaving: Torlas introduced the concept of flow interleaving as a means to maximize network utilization while maintaining minimal end-to-end queuing latency. The discussion distinguished between point-to-point aggregation and more complex interleaving scenarios within the network.
Interface from Application to Deterministic Networks: Karen presented their work to provide an interface from application to deterministic networks.

Decisions and Action Items

Enhanced Detnet Data Plane: It was decided that the upcoming open meeting time slot be on Tuesdays at 8 AM US Eastern time.
Scaling Requirements Draft: Glenn Parsons suggested considering the use cases for deterministic networks. It was suggested to review the existing documents, and any comments should be sent to the mailing list.
Open Action Items: Authors were asked to self classify their mechanisms.

Next Steps

Continue discussions on the mailing list.
Coordinate with solution documents for evaluation.
Refine documents based on feedback received.
Further develop Yang models.

Session Date/Time: 27 Jul 2023 22:30

detnet

Summary

This was a joint detnet and raw working group meeting at IETF 117. The main topics included the merging of the RAW working group back into detnet, a review of RAW documents and their status, discussion of the DetNet charter update, and presentations on 5G DetNet and traffic engineering extensions for DetNet.

Key Discussion Points

RAW/DetNet Merge: The RAW working group is merging back into detnet. Open questions remain regarding the status of RAW documents.
RAW Document Status: A review of the status of various RAW documents, including architecture, technology, OEM support, framework, and industrial requirements drafts. The disposition of each document was discussed, including actions for the detnet chairs and potential new co-authors.
DetNet Charter Update: Proposed changes to the DetNet charter were presented, primarily incorporating text from the RAW charter. The chairs solicited feedback from the working group, noting that the AD ultimately decides on the changes.
Architecture Document Discussion: A detailed discussion around the RAW architecture document, focusing on terminology. Key points included the use of "protection path," the potential introduction and retraction of the term "lane," and the need for new terminology for "cross lane" concepts. Discussion focused on clarifying the roles and interactions of components, including the PSC/PLR and asynchronous control plane functions. New terminology like 'recovery graph' was also proposed.
5G DetNet Presentation: A presentation on a 5GS logical DetNet node, with a focus on YANG model extensions. Discussed 5G architecture, 2-way communication between 5G and DetNet domains, and proposed enhancements to the YANG configuration.
Traffic Engineering Extensions for DetNet: A presentation on traffic engineering extensions for DetNet to support differentiated queues. Discussed the need for different SLA guarantees, policy-based path steering, resource management, a layered model, and deterministic link modules. Concerns were raised about the similarity to existing IETF topology models.

Decisions and Action Items

RAW Industrial Requirements Document: Carlos will check in with existing co-authors, and if they don't respond will update the document.
RAW Architecture Document:
- The authors are awaiting approval from all contributors regarding IPR status.
- A new deadline for the working group last call will be set.
- Once the new version hits the mailing list, DetNet community should review the terminology.
PLR (Point of Local Repair) Terminology: Officially adopt PLR in place of PSC (Path State Component).
Track Terminology: Adopt the term 'recovery graph' in place of 'track'.

Next Steps

DetNet chairs to send the proposed charter changes to the mailing list for further comments.
Authors of the RAW architecture document to continue updating the document based on feedback and to solicit further review from the DetNet community.
The 5G DetNet authors will further refine their work, considering potential reuse of existing YANG models, and investigate whether the work requires a new document or can be added to existing documents.
DetNet community should provide feedback on the traffic engineering extensions presentation, considering if the approach is the correct way to address differentiated queues.