Minutes interim-2016-6tisch-17: Fri 15:00

Meeting Minutes IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch) WG
Title Minutes interim-2016-6tisch-17: Fri 15:00
State Active
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Last updated 2016-12-13

Meeting Minutes

# Minutes, 09 December 2016 interim, 6TiSCH WG #

Note: timestamps in PDT.

Connection details

* Date: 7-8am Pacific:
* Webex link:
    * Meeting number (access code): 203 224 694
    * Meeting password: sixtus (749887 from phones)
* Webex Recording:
* Slides:

Taking notes _(using Etherpad)_

1. Pascal Thubert
1. Malisa Vucinic

Present _(alphabetically)_

1. Geraldine Texier
1. Jonathan Munoz
1. Malisa Vucinic
1. Maria Rita Palattella
1. Nicola Accettura
1. Pascal Thubert
1. Randy Turner
1. SVR Anad
1. Simon Duquennoy
1. Tengfei Chang
1. Thomas Watteyne
1. Qin Wang
1. Xavi Vilajosana
1. Yasuyuki Tanaka

Action Items

* **Michael** and **Malisa** to resubmit both sec drafts with name to ietf-
with NO change. * **Randy** to start a discussion on the ML about TSCH over
sub-GHz PHY layers. * **Thomas** to organize a 6P DT meeting on 12/16 at the
6TiSCH interim time to progress on 6top. * **Diego** to publish consensus about
SF0 * **Maria Rita** to publish what consensus is obtained on the terminology
and ask again in the terms for which consensus was not reached


* Administrivia [2min]
    * Approval agenda
    * Approval minutes last call
* Status of drafts [Chairs] [5min]
* Update on security [Michael, chairs] [5min]
* Wrap up ML discussions on 6top [Thomas] [25min]
* Next steps for SF0 [Pascal] [15min]
* AOB [3min]


* _[07.04]_ meeting starts
    * recording starts
    * chairs remind Note Well
* _[07.07]_ Administrivia [2min]
    * Approval agenda
    > Tengfei asks to talk about relocation format
    > Maria Rita asks to discuss on the terminology
    > updated agenda proposed and approved, see slide
    * Approval minutes last call
    > No issues rasied, minutes approved
* _[07.10]_ Status of drafts (**Pascal Thubert**)
    *  minimal draft in IETF LC.
    * both security draft adopted.
    > Action item: **Michael** and **Malisa**, please resubmit both sec
    drafts with name to ietf- with NO change. * RFC8025 (paging dispatch) ->
    published * routing dispatch, published in 3-4 months * BBR draft update *
    dao-projection, accepted at ROLL. Potential replacement of P2P RPL, based
    on AODV.
* _[07.16]_ Update on draft-ietf-6tisch-minimal (**Thomas Watteyne**)
    * presents on behalf of Xavi, who is connected through voice only
    * AD review from Suresh triggered lots of reshuffling
    * there should be no changes in technical content but should be verified
    * Thomas goes through the changes -- exact same contents but presented
    differently. * Organized by layers, e.g. setting 15.4, setting RPL, etc...
    * **Xavi**: following Suresh's comments found some duplicates and
* _[07.19]_ Misc discussion on the Mailing List (**Thomas Watteyne**)
    * Timeslot template and slot duration
    * Question: what happens if my packet is too long to finish before the end
    of the slot? * Answer: looking upon the figure 3 about the timeslot
    template, if the packet is too long then the slot duration needs to be
    extend to fit the long packet. * **Randy**: problem in sub-GHz band, slow
    bit rate, we overrun slot boundaries because some beacons have many IEs.
    2015 spec does not preclude overrun. * **Pascal**: do you use CCA? *
    **Randy** we looked at fragmentation, but seems heavy. We tried CCA. I was
    not sure how to take slow bit rate into account. My interpretations that we
    are willing to trade fragmentation overhead to keep slots aligned. *
    **Pascal**: WISA uses two timeslots that can be grouped as one. Can we use
    a similar technique? * **Jonathan**: Alternative would be to use a bigger
    timeslot for sub-GHz. Lowest datarate would be 50 kbps. * **Randy**: we
    advertise an MTU of 1280 although the 15.4g defines a 2047 bytes MTU. *
    **Thomas**: multiple people working on that, potential for a draft
    explaining how to adapt a schedule for low speeds. * **Simon**: solution
    for me was redefine 30ms time slots * **Jonathan**: fitting to the worst
    case > Action item: **Randy** to start a discussion on the ML about TSCH
    over sub-GHz PHY layers.
* _[07.32]_ Update on security (**Malisa Vucinic**)
    * The DT met twice during past 2 weeks, to speed up work.
    * presented the minimal-security draft again and we discussed address
    assignment. * Tero indicatd that short addresses need a lease time, key
    identifier missing for link-layer. * Good news: well-known URI for the JCE
    is feasible; but should be an URI in .arpa. * Max indicated that we need a
    special attribute in the certificate for JCE. * Discussions on certificate
    enrollment using EST as done in ANIMA and how to adapt it to 6TiSCH.
* Wrap up ML discussions on 6top (**Thomas Watteyne**)
    * Lot of work in coming slides, not enough time.
    * can everyone join next week, same time?
    > time works for all 6P key contributors
    * proposal is to have a side meeting on 6top protocol.
    > Action item: Thomas to organize a 6P DT meeting on 12/16 at the 6TiSCH
    interim time to progress on 6top. * The slides will be published and a
    meeting next week will wrap it up. * Let's talk about 6P signaling traffic
    now. What cells is that traffic sent on. No doc says how traffic is
    segregated between minimal and dedicated slots. Which traffic goes where?
    Proposal to to use minimal as a last resort only. * **Simon**: Contiki
    implementation uses shared slot iff there no dedicated slot. * **Tengfei**:
    OpenWSN feedback: in 2-step transaction, if we miss the last ack, it's
    possible to have a single-sided schedule * **Pascal**: better no create a
    transmit slot if there is no positive ack. * **Simon**: that's better, it
    maybe that the receiver listens if the ack was sent and missed, but that is
    not as bad. * **Thomas**: We'll eventually realize at the next sync. Should
    not be that often. * **Nicola**: I found the same thing when implementing
    on OpenWSN. It is a problem that can happen, more frequently if using
    simulation motes.
* Next steps for SF0 (**Thomas Watteyne**)
    * Diego not here, as editor, we need him to make consensus.
    * Will ask Diego to propose a consensus
    > Action item: **Diego** to publish consensus about SF0
* Terminology (**Maria Rita Palattella**)
    * Xavi asked to add CCA, Pascal asked to prepare for last call.
    * I went through the draft and identified terms that are obsolete, or very
    generic, got feedback on ML agreeing to remove those terms. * No consensus
    on removing CDU matrix, same for bundle. * Pending the definition of
    deterministic networks. * **Pascal**: recommends to publish new version of
    terminology with consensus. > Action item: **Maria Rita** to publish
    what consensus is obtained on the terminology and ask again in the terms
    for which consensus was not reached
* Rechartering
    * no time.
    * **Malisa**:
        * working on 6TiSCH simulator in Python.
        * Simulates on a high level the behavior of the 6TiSCH stack.
        * Just finished the implementation of shared slots.
        * Contributions are welcome.
        * https://bitbucket.org/6tisch/simulator/