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Minutes Webex 08 March 2013, 6TSCH group

Note: timestamps in PST.

Present (alphabetically)

  1. Herman Storey
  2. Maria Rita Palattella
  3. Norman Finn
  4. Pascal Thubert
  5. Qin Wang
  6. Shitanshu Shah
  7. Thomas Watteyne
  8. Tina Tsou
  9. Tom Phinney
  10. Xavi Vilajosana


  • Introduction to the terminology draft [10min] [Maria Rita]
  • Diffserv Recommendations for LLN class of traffic [5min] [Shitanshu]
  • Agenda for new week meetings [10min] [Pascal]
  • Changes in other drafts [10min]
    • draft-watteyne-6tsch-tsch-lln-context [Thomas]
    • draft-wang-6tsch-6tus [Qin]
    • draft-thubert-6tsch-architecture [Pascal]
  • Mailing list discussions [30min]
    • DSCPs and priorities [Thomas]
    • imux/mux [Qin]

Minutes: [08.04] meeting starts [08.05] Introduction to the new terminology draft [Maria Rita] * [Pascal] This draft extends ROLL and autoconf terminology, which are included as references. * [Maria Rita] Presents slides. * [Maria Rita] draft was triggered by the fact that "link" and "path" have different meaning in TSCH and IETF parlance. * [Maria Rita] "Cell": Single element in the TSCH schedule. Replaces "link" term in TSCH. * [Maria Rita] "Bundle": A group of equivalent scheduled cells. Replaces (although not exactly) "path" term in TSCH. * [Maria Rita] Draft there to avoid confusion, we will include other terms as work progresses. * [Maria Rita] Draft will be published on Monday. [08.14] Diffserv Recommendations for LLN class of traffic [Shitanshu] * draft at * Shitanshu presents slides. * Context: this draft was presented at the last IETF meeting in Atlanta. * Goal: using Diffserv in context of LLN * Motivation: RFC4594 is well documented recommendation for traditional classes of traffic. Yet, does not cover LLN. What this draft does it: * categorize LLN * lists explicit recommendations for LLN * always keeping RFC4594 as a reference * source points to mark appropriate DSCP code point * LLN Traffic Classes identified from ROLL requirement drafts * 6 categories: alerts/alarms, control signals, deterministic control signals, Video Monitoring/feed, Query-based data, Periodic Reporting/log & software downloads. * each class characterized in terms of loss, delay and jitter. Some classes are different from RFC4594, justifying the need for this new draft. Example: deterministic control signals. * [Tom] Alerts/Alarms traffic are bursty because multiple network elements can signal the same physical events (e.g. explosion). * [Herman] You don't want to loose any alert/alarm packets * [Shitanshu] Agreed, will update draft. * [Herman] Is there a class for network management? * [Pascal] In some cases, network control needs to be the highest priority since network falls apart when no network control packets can be transmitted. * [Pascal] DSCP will play key role in packet priority. There is no DSCP for flow priority. * [Pascal] PHB means "per hop behavior" * [Shitanshu] Draft proposed code-point EF * [Herman] Why are emergency action outside of IP networks? * [Shitanshu] Other techniques are used which are not IP. * [Herman] There are IP-based solutions. Operate as dedicated network, not connected to complete Internet (non routable subnet), but use IP address. * [Shitanshu] We can remove the term IP. [08.35] Agenda for new week meetings [Pascal] * Tuesday (Caribbean 2): * admin * we will have 5-10min during the ROLL meeting to present 6tsch * 6tsch meeting follows ROLL meeting, same room * we need to leave 15min before end to set up next meeting, so we will really only have one hour. * we will have projector, not clear whether we will be able to provide live online feed. * Goal: prepare for successful BoF in Berlin * Scope: the backbone with PCE (Path Computation Entity) and one or more LLN running 6LoWPAN, 6TSCH, RPL. * we use draft-phinney-roll-rpl-industrial-applicability as a starting point. * goals and deliverables: * informational: LLN context, architecture, terminology * new: 6tus, protocol for reserving track * adapt existing: OF for RPL, fragment forwarding (problems because don't have DSCP) * extern docs: backbone router (from 6MAN), PCE (is a WG, need to coordinate) * dependencies and liaison: * IEEE 802.1TSN (Norman) * ISA100.20 are defining arbstraction for management layer to manage the managers (e.g. blacklist channels). We could use same formats. * IoT6. European project. They use very similar architecture as ours. * Wednesday (Boca 2) * admin: * in Boca 2, which we can stay in past 1pm. * we will go over different drafts * draft-phinney-roll-rpl-industrial-applicability. * published at * [Tom] Analysis of classifications of types of communications that occur. Applies to all automation systems, worked out over years by many people. * [Pascal] Good source of inspiration. * draft-watteyne-6tsch-tsch-lln-context * published at * [Thomas] do not expect -02 for Orlando, but will need rewording for new terminology. * draft-wang-6tsch-6tus * [Pascal] Caution, we cannot reinvent MPLS. * [Xavi] will be published on Monday. * draft-palattella-6tsch-terminology * see presentation above * will be published on Monday. * draft-thubert-6tsch-architecture * [Pascal] will be work-in-progress for a long time, since incorporates changes/concepts from other drafts. * [Pascal] More text to follow: network synchronization, 6tus, management, etc. * [Thomas] Can be seen a index for other drafts, could serve as first draft to read when familiarizing with 6tsch. [08.55] Priority discussion * [Thomas] We don't have much time left, so instead of starting discussion, will prepare slides for Wednesday meeting. * [Pascal] Will add slot for Wednesday meeting. * [Pascal] Pascal will meet with Shitanshu on Monday morning, Thomas will meet with Pascal on Monday evening and Tuesday. [10.00] * [Thomas] Will be meeting stay at this time? * [Tom,Pascal] For the moment yes * [Pascal] There is not call next week because of IETF meeting. [10.05]* Meeting ends.