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Minutes, December 5 2014 interim, 6TiSCH WG

Note: timestamps in PDT.

Connection details


Taking notes (using Etherpad)

  1. Dominique Barthel
  2. Thomas Watteyne
  3. Diego Dujovne
  4. Michael Richardson
  5. Pascal Thubert


  1. Alfredo Grieco
  2. Deji Chen
  3. Diego Dujovne
  4. Dominique Barthel
  5. Giuseppe Piro
  6. Guillaume Gaillard
  7. Malisa Vucinic
  8. Maria Rita Palattella
  9. Michael Richardson
  10. Nicola Accettura
  11. Pascal Thubert
  12. Pat Kinney
  13. Pouria Zand
  14. Raghuram Sudhaakar
  15. Sedat Gormus
  16. Thomas Watteyne
  17. ? unknown call in user ?

Action Items

  1. Pascal to announce Last call completion and signal for IESG review process
  2. Pascal to start LC for the Minimal draft
  3. Thomas to publish a TSCH draft addressing LC questions
  4. Thomas to start LC for CoAP draft
  5. Raghuram to add a disclaimer for the reviewers indicating that the changes may occur in RFC Ed Q due to dependencies on CoMI



  • [08.05] Meeting starts
  • [08.07] Administrivia
    • Approval agenda

      Agenda approved

    • Approval minutes IETF

      Minutes of IETF approved. No comments on the call. (Can be changed until Dec 24th)

  • [08.09] IETF91 Outcome
    • Overview
      • Discuss drafts
    • Last Call for draft-ietf-6tisch-tsch
      • Last Called launched last week, 2 comments received.
      • consensus reached. Pascal (shepherd) will send to IESG, hopefully before Xmas.
      • Thomas will do the change, asap.
    • Update / Last Call for draft-ietf-6tisch-minimal
      • Concerns about the security text at the IETF meeting. Xavi wrote the changes and published a new version.
      • Pascal believes we are ready for last call. No objection on this call.
      • Pascal will issue a 2-week Last Call shortly, to end before end-of-year vacations.
      • Only question still in the air is NHC vs. ???. Can do an update during IESG discussion. Not blocking for submission, Pascal believes.
    • Update / Last Call for draft-ietf-6tisch-coap
      • Thomas: this -coap draft and CoMI overlap. CoMI is superset so trying to reference CoMi in the CoAP draft.
      • Raghuram: Aligned the CoAP draft with the current version of CoMI; indicating that CoMI will supersede if a discrepancy occurs. Draft presents examples of how CoMI is used
      • Thomas: draft is absolutely needed.
      • Raghuram: definition of URIs and resources were needed and stable, but the examples are subject to change with CoMI.
      • Thomas: are we there yet? Opinions on the call?
      • Pascal: what's missing?
      • Thomas: was updated yesterday
      • Raghuram: payload format not fixed. Only point of contention with CoMI. Does not expect CoMI to change any more.
      • Pascal: will stay in Ed. queue anyway, waiting for CoMI, if we list it as a normative reference. Still good to have our doc ready to encourage implementations, we should not keep it on hold.
      • Pascal: believes that changes are minor, recommends to do the LC and apply changes per comments received.
      • Raghuram: will put in datatracker and do changes.
    • Other next steps (architecture & security, terminology)
      • 6tisch-architecture draft. Shephard not Thomas or Pascal because co-authored. Michael and RenĂ© will provide text for the security section. Will Last Call early next year (did I hear this right ????).
      • -terminology Michael: security terms text was provided yesterday.
      • security will not be discussed in this call because of tight agenda, but rather in the next call TW: two security calls since IETF91. Minutes to come. Will discuss security again at the next 6tisch call.
  • [08.32] update IEEE802.15.4-2015 (Pat Kinney)
    • 15.4 undergoing a revision. Revision using 2011 as a baseline. 7 amendments to be rolled up.
    • Hoping for approval mid-august 2015.
    • Size reduction - 661 pages to go down. SCrubbing acronyms, definition, bib. Eliminate dup definition.
    • Other groups can get assigned numbers. Relevance to 6tisch being discussed.
    • IE ID's changed.
    • Deleted Terms. More to go.
    • Changes to IFS - fixed size
    • Changes within TSCH - lot of them. TSCH Terminology harmonized with rest of the standard.
    • CSMA-CA flow charts being redrawn to show TSCH. Consistency improved.
    • [TW] : [PK] : Mac needs to construct the frame and can be tolerated by PHY.
    • CSMA-CA and CCA are focused on coexistence within the same band ONLY.
    • longer than 20us, will back off due to IEEE802.11
    • Priority mechanism required between different nodes. PCA is the way to do it. Working to get it harmonized.
    • Trying to clarify when to use what and how.
    • Corrections on the Security area
    • Security changes: State machines, frame counters, new frame types, TSCH: removed 5 octet
    • Question from Thomas; Answer: Only one size frame counter.
    • State machines design under heavy work. Ask for changes if states dissipated.
    • nonce generation for TSCH .. not allowing short-addresses in ??? field.
    • Short address is not unique: is ambiguous when outside. It can be reused. Thomas: out of scope from 802.15.4 Pat: Yes, from upper layers. Short address inappropriate to be used.
    • Thomas: Increment allowed, usage of the ASN avoids tracking when reusing the same short address. Pat: SHort Address can allow the key to be exposed (as a general case)
    • Pat: There is a possibility, it must be discussed.
    • Pat: Short Address:...
    • Thomas: can be
    • Thomas: Example: Short Address asked from the node to the PCE
    • Michael: Network Wide key.
    • Pascal: Bring this to the ML
    • Pat goes on. Protocol Implementation Conformance Statement
    • Pat: Fast forward on slides.
    • Pat: TG4.. q: ultra low power, r: ranging
    • 802.15.9: key management, letter ballot
    • 802.15.10: layer2 routing
    • reflector information to follow.
  • [08.55] AOB
    • Thomas: Security discussions on 6TiSCH -> state machines
    • Pat: Will build a document that can be distributed
    • Thomas: PCA tracks? Pat: Simple on the mechanism, tough in the details. 802.15.4k Priority Channel Access. Contention access period. Check for the concepts. 6top must tell the priority of these packets.
    • Thomas: Capture effect questions for the next call.
    • Thomas: Any other questions for Pat? Go to the ML.
    • Next security call on Tuesdays 9-16 December 11AM EST 1300 UTC
    • See you on next call.
  • [09.03] Meeting ends