# DetNet Minutes for IETF 116 (Yokahama and Online) {#detnet-minutes-for-ietf-116-yokahama-and-online} WG ICS: https://datatracker.ietf.org/meeting/upcoming.ics?filters=detnet Datatracker: https://datatracker.ietf.org/group/detnet/about/ # Thursday, March 30, 2023 - Session I {#thursday-march-30-2023---session-i} 09:30-11:30 JST (00:30 – 02:30 UTC) 3F G303 Materials: https://datatracker.ietf.org/meeting/116/session/detnet Note taking: https://notes.ietf.org/notes-ietf-116-detnet#both Meetecho: https://meetings.conf.meetecho.com/ietf116/?group=detnet&short=detnet&item=1 Onsite tool: https://meetings.conf.meetecho.com/onsite116/?group=detnet&short=detnet&item=1 Audio stream: https://mp3.conf.meetecho.com/ietf116/detnet/1.m3u Chat: https://zulip.ietf.org/#narrow/stream/detnet Session ICS: https://datatracker.ietf.org/meeting/116/sessions/detnet.ics YouTube: https://www.youtube.com/watch?v=mF2CE9utDZU ## Slot Start Duration Information {#slot-start--duration-information} ## 1 09:30 8 min Title: Intro, WG Status, Draft Status {#1-0930-8-min-title-intro-wg-status-draft-status} Presenter: Chairs Scott Mansfield: WRT ITU-T liaison 1 (slide 9): I want to talk about the subset of RFCs that should be shared with ITU-T - let me know, they are not due until 18Apr23 so have some time. Scott Mansfield: WRT ITU-T liaison 2 (slide 10): I would like to respond back to ITUT back on this, their next study group meeting not til July. We want to keep pressure up on what this group is doing, to set up guide rails for that group. Let me know if you know of anything specific that we need to include in the response. Lou Berger: Can you propose a response? Scott Mansfield: Given guidance e.g. of hot topics, yes, can do, we can take this offline. ## 2 09:38 10 min Title: Deterministic Networking (DetNet) Controller Plane Framework {#2-0938-10-min-title-deterministic-networking-detnet-controller-plane-framework} Link: https://datatracker.ietf.org/doc/draft-ietf-detnet-controller-plane-framework-04 Presenter: Xuesong Geng Quan Xiong: WRT Slide Doc Structure Update. Want to put Multi-Domain Aspects discussion into Controller Plane section, sec 3. Xuesong Geng: We can discuss with Carlos - we were considering a separate section to make it easier for the reader to find. Quan Xiong: Need to consider distributed or hybrid control plane. Need more discussion on list. Path establishment and reservation - can be implemented separately, should not be joined. Xuesong Geng: In Controller Plane architecture draft, we covered 3 cases - central, hybrid, and distributed. The point here is to make more logical organization, but the implementation would be the same. Lou Berger: Good discussion, look forward to discussion on list. Now is a good time for the WG to review the latest version of the draft and send comments to the list. ## 3 09:48 10 min Title: Update from Interim Meeting, Plan for open meetings {#3-0948-10-min-title-update-from-interim-meeting-plan-for-open-meetings} Link: https://datatracker.ietf.org/meeting/interim-2023-detnet-01/session/detnet Presenter: David Black (remote) Lou Berger: Regarding schedule slide: We are planning a series of meetings to go over proposals. We want to establish directions to recommend to WG to bring to list for consensus. Intent is also to record the meetings so that if you can't attend, you can view it later. Plan is now to use Webex, but could move to Meeteccho. We tried Webex at previous meeting - apparently it recorded a lot of extra time, so not ideal, but worth a try, can adjust as necessary. Keep chairs in loop if there are problems or success with the process. Thanks to David Black for help with this. ## 4 9:52 10 min Title: Requirements for Scaling Deterministic Networks {#4-952-10-min--title-requirements-for-scaling-deterministic-networks} Draft: https://datatracker.ietf.org/doc/draft-ietf-detnet-scaling-requirements-01 Presenter: Peng Liu Greg Mirsky: I can imagine why time sync might not be critical for data plane itself, but how can the one-way delay be measured w/o clock synchronization? I am not aware of any such method. Lou Berger: This draft is about requirements. Your question is about implementation; it is not a first level requirement, but rather a derived requirement. Greg Mirsky: But if requirement is to be able to accurately measure one-way delay... Peng Liu: We had a one-way delay discussion before... Lou Berger: Need to take this to list. It is a great discussion point, but need to deecide where to capture it, since we need to capture it for sure. David Black: I suggest separating "measuring" from "achieving" - one can perhaps achieve without measuring it, e.g. if you know the delays of each of the segments, you can add them together to get the end result without explicitly measuring the end-to-end delay. Greg Mirsky: (from chat) As the saying goes "You cannot control, what you cannot measure". David Black: (reply, from chat) There's at least one proposed solution that does that piecewise rather than end-to-end. (David was referring to ADN, agenda item 6) Toerless Eckert: the document is on the WG github, please feel free to raise issues with the document there. Lou Berger: As long as we keep in mind that consensus is via the list. ## 5 10:03 10 min Title: Deterministic Networking (DetNet) Topology YANG Model {#5-1003-10-min--title-deterministic-networking-detnet-topology-yang-model} Draft: https://datatracker.ietf.org/doc/draft-ietf-detnet-topology-yang-00 Presenter: Xuesong Geng and Zhenqiang Li Xuesong Geng: There is an updated version of the draft. Next step is to activate it. Prepare new doc on how to use this YANG model, and want to ask WG about this proposal. Just want to publish and get discussion going again. Dean Bogdanovic: There is RFC8345 Network Topo yang model, why not use that and just augment with DetNet specificities? Xuesong Geng: Want to also consider queueing delays. Tianji Jiang: There are lots of additional parameters in 5G, like interval mean packet - not just delay. Lou Berger: This is building on TEAS work, topologies, building on other work, not starting from scratch. Dean Bogdanovic: TEAS work is deriving from RFC8345 ## 6 10:18 8 min Title: Asynchronous Deterministic Networking Framework for Large-Scale Networks {#6-1018-8-min-title-asynchronous-deterministic-networking-framework-for-large-scale-networks} Draft https://datatracker.ietf.org/doc/draft-joung-detnet-asynch-detnet-framework-01 Presenter: Jinoo Joung Lou Berger: sorry no time now for comments. This topic will be the subject of future discussion meetings, will have more time to discuss there. ## 7 10:25 8 min Title: DetNet Data Plane - TCQF for bounded latency with low jitter in large scale DetNets {#7-1025-8-min-title-detnet-data-plane---tcqf-for-bounded-latency-with-low-jitter-in-large-scale-detnets} Draft: https://datatracker.ietf.org/doc/draft-eckert-detnet-tcqf-02 Presenter: Toerless Eckert Lou Berger: Good discussion, we will have more discussion in open meetings to come. ## 8 10:34 8 min Title: Deadline Based Deterministic Forwarding {#8-1034-8-min-title-deadline-based-deterministic-forwarding} Draft: https://datatracker.ietf.org/doc/draft-peng-detnet-deadline-based-forwarding-05 Presenter: Shaofu Peng Lou Berger: Please work with David Black to schedule further discussion at side meetings. ## 9 10:42 8 min Title: DetNet Enhanced Data Plane {#9-1042-8-min-title-detnet-enhanced-data-plane} Draft: https://datatracker.ietf.org/doc/draft-yzz-detnet-enhanced-data-plane-02 Presenter: Xuesong Geng Quan Xiong: You mentioned flow aggregation and priority, and time info. But enhancement is for the forwarding layer - what is the relation to service layer? Xuesong Geng: Service layer is not only about flow label for PREOF, but also in ipv4/6 data plane there is flow ID (e.g. n-tuples) - this is a general concept, not just flow label as already defined. Quan Xiong: Need more discussion relating forwarding layer and service layer. Xuesong Geng: Bounded latency belongs to forwarding layer, sure. Quan Xiong: Still could have discussion. Greg Mirsky: Going forward, please use current MPLS terminology - some field names shown are very old, obsolete now. Also, what is your intention for how to carry shaper credit information? If you want to carry the quantity, i.e. amount credited, you can look at MPLS Network Action work to add ancillary data in label stack. Xuesong Geng: I am not an MPLS expert, and this is an early proposal, but will look at it. Greg Mirsky: It is good to understand what work is available to base this new work on. ## 10 10:50 8 min Title: Data Fields for DetNet Enhanced Data Plane {#10-1050-8-min-title-data-fields-for-detnet-enhanced-data-plane} Draft: https://datatracker.ietf.org/doc/draft-xiong-detnet-data-fields-edp-00 Presenter: Quan Xiong Lou Berger: Clearly there is interest in doing additions to data plane from the queuing side; it would be good to have both of these discussions proceed in lockstep. ## 11 10:58 8 min Title: DetNet Control Plane: VPFC Planning Scheme Based on VPFP in Large-scale Deterministic Networks {#11-1058-8-min-title-detnet-control-plane-vpfc-planning-scheme-based-on-vpfp-in-large-scale-deterministic-networks} Draft: https://datatracker.ietf.org/doc/draft-guo-detnet-vpfc-planning-01 Presenter: Kehan Yao 姚柯翰 Xuesong Geng: I notice that this draft is shown as standards track, but it discusses implementation status. I suggest to the authors to change this to informational track. Kehan Yao: We will consider this. Quan Xiong: This is a good proposal for queueing configuration model, but it is explicitly based on cycle mechanism - please consider all queueing mechanisms. Kehan Yao: We will consider this in future versions. ## 12 11:06 8 min Title: Criteria and Assessment for DetNet Services Forwarding Plane Methods {#12-1106-8-min-title-criteria-and-assessment-for-detnet-services-forwarding-plane-methods} Draft: https://datatracker.ietf.org/doc/draft-eckert-detnet-criteria-assessment-00 Speaker: Toerless Eckert Greg Mirsky: You said that in uncongested overprovisioned systems there is no delay - I think you meant no jitter, right? Toerless Eckert: Right - if uncongested and overprovisioned, there is no queing delay variation, but delay still exists. Lou Berger: Please take to the list. This highlights the importance of common terminology, something to add to criteria discussion. ## 13 11:14 8 min Title: YANG Data Model for DetNet Mapping with Network Slice {#13-1114-8-min-title-yang-data-model-for-detnet-mapping-with-network-slice} Draft: https://datatracker.ietf.org/doc/draft-sw-detnet-network-slice-mapping-yang-02 Presenter: Xueyan Song Lou Berger: You presented this before, and we discusssed alignment with TEAS - I suggest you send a message to them letting them know that this work is happening here and being discussed here. Xueyan Song: OK ## 14 11:22 8 min Title: Using Deterministic Networks for Industry Operations and Control {#14-1122--8-min-title-using-deterministic-networks-for-industry-operations-and-control} Draft: https://datatracker.ietf.org/doc/draft-km-detnet-for-ocn-00 Presenter: Kiran Makhijani Dean Bogdanovic: I agree that the app should not have to understand the internals of DetNet, but app design is not black/white, or only considering the action in the cloud. Industrial applications using realtime operating systems are often organized as high level swarms. For example in automotive, many calculations are done in the car, but then global context is updated to the cloud only at longer intervals. In an industrial environment, for example robots, they often work like swarms, and the computation that is done in the cloud is then sent to a local controller(s) to control the swarm(s). So in such cases it is not so clearly delineated, it is more granular, so perhaps Detnet would only need to be deployed on local devices. Kiran Makhijani: But there are many scenarios, and yes DetNet may only apply to some. For example we may have many sites of factory floors, for which we want to control the supply chain, so that doesn't need to be local at all. Lou Berger: This is interesting discussion, since it is less about the data plane side, so it is a different sort of topic for the DetNet WG - we look forward to more on-list discussion on this, and in open meetings (note that webexes are already announced for some). Lou Berger: Thanks to everyone here and online - see you in San Francisco!! Adjourn 11:30 Self identified note takers: Ethan Grossman Lou Berger