Minutes IETF104: 6tisch

Meeting Minutes IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch) WG
Title Minutes IETF104: 6tisch
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Last updated 2019-04-05

Meeting Minutes

   # Minutes, IETF 104 6TiSCH WG Meeting #

Note: these minutes are formatted using Markdown

Agenda and Meeting information

Meeting        :   IETF104 Monday, March 25, 2019 (CET)
Time           :   11:20-12:20 Monday Morning session II (60min)
Location       :   Congress Hall 3, Hilton Prague
Chairs         :   Pascal Thubert pthubert@cisco.com
                   Thomas Watteyne thomas.watteyne@inria.fr
Responsible AD :   Suresh Krishnan
Live minutes   :   https://etherpad.tools.ietf.org/p/notes-ietf-104-6tisch
Live feeds     :   https://datatracker.ietf.org/meeting/agenda/

Other URLs     :   https://tools.ietf.org/wg/6tisch/
               :   https://datatracker.ietf.org/wg/6tisch/
               :   https://www.ietf.org/mailman/listinfo/6tisch
               :   https://bitbucket.org/6tisch

11:20 Intro and Status                       (Chairs)            [10mn]
   * Note-Well, Blue Sheets, Scribes, Agenda Bashing
   * Status Documents
   * Status 6lo / ROLL
   * Milestones
   * Action Plan

11:30 Architecture
   * draft-ietf-6tisch-architecture         (Pascal Thubert)    [ 5mn]

11:35 Minimal Security
   * draft-ietf-6tisch-minimal-security     (Malisa Vucinic)    [10mn]

11:45 Dynamic Scheduling
   * draft-ietf-6tisch-msf                  (Tengfei Chang)     [10mn]
   * draft-tiloca-6tisch-robust-scheduling  (Marco Tiloca)      [ 5mn]

12:00 Misc
   * OpenBenchmark - Continuous delivery benchmarking for 6TiSCH
                                            (Bozidar Skrbic)    [ 5mn]
   * Showing the outcome from hackathon     (Tengfei Chang)
                                            (Malisa Vucinic)    [ 5mn]
12:10 Michael's drafts
   * draft-ietf-6tisch-enrollment-enhanced-beacon               [ 5mn]
   * draft-ietf-6tisch-dtsecurity-zerotouch-join                [ 5mn]

Any Other Business                          (Chairs)            [ QS ]


* slides: https://datatracker.ietf.org/meeting/104/session/6tisch
* audio recording:
https://www.ietf.org/audio/ietf104/ietf104-congresshall3-20190325-1120.mp3 *
Meethecho recording (audio+video):


* notetaker 1: **Dominique Barthel**
* notetaker 2: **Fabrice Theoleyre**
* notetaker 3: **Xavi Vilajosana**
* Jabber scribe: **Tengfei Chang**

Action items

* **Pascal** and **Suresh** to discuss the status of
`draft-ietf-6tisch-architecture`; it is now Proposed Standard, may change. *
**Tengfei** to publish a new version of `draft-ietf-6tisch-msf`. _Target
deadline: **8 April 2019**_. * **Yasuyuki Tanaka**, **Thomas Watteyne**,
**Fabrice Theoleyre** to review new version of `draft-ietf-6tisch-msf` after
Tengfei publishes it. _Target deadline: **23 April 2019**_. * **Xavi
Vilajosana**, **Tengfei Chang**, **Pascal Thubert** to review
`draft-tiloca-6tisch-robust-scheduling`. _Target deadline: **25 April 2019**_.


_(This summary is also posted in the INT area wiki,

During IETF104, the 6TiSCH WG had a WG meeting, and participated in the

The WG meeting covered 6 drafts:

* `draft-ietf-6tisch-architecture` has received early reviews. Input during the
WG meeting was that the use of terminology should be more homogeneous. Suresh
Krishnan asked to discuss with Pascal Thubert the intended status of the draft.
* `draft-ietf-6tisch-minimal-security` has just passed a second WGLC. During
this, an issue was raised, for which the Malisa Vucinic (editor) proposed 3
possible resolutions. Malisa Vucinic and Goran Selander (reviewer) will work
together on a resolution, which Malisa will implement. Once the new version of
the draft is published, the WG will push it to the IESG. *
`draft-ietf-6tisch-msf` has received comments from 3 review. Tengfei Chang will
publish a new version of the draft which integrates those comments, after which
Yasuyuki Tanaka, Thomas Watteyne and Fabrice Theoleyre have agreed to review
it. Once those reviews are integrated, a WGLC will be issued. *
`draft-tiloca-6tisch-robust-scheduling` was presented for the second time to
the WG, and now integrates changes from the previous presentation. Marco Tiloca
asked for reviews: Xavi Vilajosana, Tengfei Chang and Pascal Thubert
volunteered to do a review within a month. * An update of
`draft-ietf-6tisch-dtsecurity-zerotouch-join` was presented by Michael
Richardson, who flags the fact that some of that work is blocked by the fact
that the EDHOC draft still doesn't have a home. * Michael Richardson also
presented `draft-ietf-6tisch-enrollment-enhanced-beacon`. Author Diego Dujovne
will edit the introductory text of the draft (which has been stable), after
which a WGLC will be issued.

The WG meeting also highlighted three implementation-related elements:

* the hackathon, to which the 6TiSCH WG participated with the OpenWSN
implementation (http://www.openwsn.org/), which now contains a dashboard to
extract the implementation's performance * the 6TiSCH Open Data Action
(https://benchmark.6tis.ch/) which aims at providing clear, unbiased, and
continuous benchmarking of 6TiSCH implementations on institutional testbeds *
the 6TiSCH simulator (https://bitbucket.org/6tisch/simulator), which implements
the full stack; the latest release (1.1.9) was done at the IETF and comes with
a nice UI


* _[11.21, expected 11.20]_ Meeting starts
    * **Thomas** reads the Note Well
    * Michael's presentation moved to the back of the agenda compared to the
    agenda slide shown.
        * online agenda up-to-date, only slide is outdated
    * Since IETF 103, several parts of the work has progressed out of 6TiSCH.
    RFC8505 has been published, OSCORE was accepted, EDHOC is still stalled. *
    Work at 6lo progressing rapidly, several drafts at last call. AP-ND passed
    WGLC. * Milestones. Still late, but not much. * Zero-touch late. Looking
    for co-authors to work on that. * Discussion about architecture. Reviewers
    comment about readibility of the draft. It is pointed that a next round of
    review is required. * Terminology and architecture have been merged *
    **Suresh Krishnan**: The detnet doc is stuck as it is being pushed to the
    standards track. Same may happen to the 6TiSCH architecture. To find a
    resolution. > **Action item**: **Pascal** and **Suresh** to discuss the
    status of `draft-ietf-6tisch-architecture`; it is now Proposed Standard,
    may change.
* _[11:25, expected 11.25]_ `draft-ietf-6tisch-architecture` (**Pascal
    * Goal of architecture is to provide a high level architecture and
    positioning of components. * Some actions after reviews have caused
    reshuffling and reorganization of the draft. * Question is whether
    terminology document has to be merged to architecture. * **Suresh**: would
    like to have terminology in the same document as architecture. * **Eliot
    Lear**: reviewed the draft. The issue is that terms are being defined at
    the beginning and then somehow redefined in the text. Pascal did a review
    and this improved. * references should go to the back. The terminology
    references are at the beginning. According to **Eliot Lear** they should be
    at the end. * **Pascal**: if one wants to understand text, need to reed
    references before, that's why put upfront. * **Eliot**: readers are
    expected to chase the references down in the back. * Feedback from other
    readers is requested. Regarding section terminology. * **Suresh**: make
    sure that the terms are all there. * Next step for Pascal: remove the
    external references from terminology section. Extract terms needed from
    there * **Suresh**: correct; List terms in terminology section and point at
    definition in other documents
* _[11.36, expected 11.35]_ `draft-ietf-6tisch-minimal-security` (**Malisa
    * discussion major issue brought up at the ML by **Goran Selander**.
    * version 9 published after Bangkok: quick summary here of the changes
    * OSCORE has been approved by IESG. There was a heavy dependency to minimal
    security. * added a parameter join rate. used by JRC to control the
    emission of EBs. To control the start/stop process of the network. *
    clarified use of blacklist. * Malisa goes through Goran's comments. *
    updated reference to section 7.5.1 at OSCORE to appending B.1.1 * Issue
    brought up by **Jim Schaad**. * There is a failure possibility of the JRC.
    If the mutable parameters stored in the JRC are lost, while still the
    Database with the keys and node id are accessible. * The new nodes have
    preserved the mutable parameters. So there is a mismatch between JRC and
    Pledge nodes. Possible nonce reuse attack. * explains the case using a
    message sequence drawing. Failure of JRC, with PSKs preserved but sequence
    numbers are lost. Opens opportunity for replay attack. * attacker can
    replay initial join request, sent it to the JRC. if the JRC accepts it, the
    JRC cannot detect that reply. The JRC will respond and result on a nonce
    reuse. Losing confidentiality property. * 3 options described:
        * 1) challenge-response based on OSCORE as appending B.2 describes (one
        additional round-trip) * 2) design of a custom sequence number sync
        mechanism. Custom for 6TiSCH. additional round-trip. * 3) require that
        mutable parameters are stored together with immutable parameters. At
        every update they must be stored in the database.
    * Question to the WG regarding point 3, should this be used? is it
    realistic? * **Thomas** (contributor): you're saying option 2 does not
    provide enough advantage compared to 1 or 3? * would be custom to 6TiSCH
    and would require more security reviews. * **Thomas**: option 3 means if
    JRC fails, need to reprovision all motes. Is this correct? * correct. *
    **Thomas**: option 1 requires additional code, additional footprint,
    additional time to download. * correct. * **Thomas**: can we make option 1
    optional? * **Thomas**: Do we need SHA1 or we can use other mechanism such
    as AES for the HKDF procedure? * Goran indicated that HKDF can rely on AES
    to save the SHA 2 code footprint by putting a wrapper to AES. * **Goran
    Selander**: HDKF algorithms shown in in table 12 of RFC8152. * **Peter Van
    der Stock**: why not find the highest used sequence number by asking all
    nodes? * **Malisa**: This is option 2. * **Thomas**: suggests to continue
    discussion on the ML.
* _[11.52, expected 11.45]_ `draft-ietf-6tisch-msf` (**Tengfei Chang**)
    * Clarified use of shared and non-shared autonomous cells
        * presentation of the non shared vs. shared autonomous cells for
        Join/6P Response/Request packets.
    * list of pending issues presented. Still there are few issues to be
    discussed. * During the join process the allocation of a autonomous cell. A
    malicious user may change EUI64 and try to fill in the memory/schedule of
    the JP with autonomous cells. * **Malisa**: in minimal security, we say
    that a separate entry should be allocated for nodes trying to join. Just
    reference that text. * **Yatch**: the join request will fill up the
    schedule anyways (memory). You need to mention this in the security
    considerations. * ok, will be addressed. * **Malisa**: Yatch saying the
    text generic enough so that pledge can be considered just a new neighbor. *
    Trickle timer with rate limiting is not clear how to be implemented. This
    will be changed by the trickle timer. * MSF version 02 implemented in the
    last OpenWSN version (REL-1.24.0). 40 mote running in Inria building in
    Paris. * **Thomas**: suggest to integrate comments, push new version and
    we'll go for WGLC. > **Action item**: **Tengfei** to publish a new
    version of `draft-ietf-6tisch-msf`. _Target deadline: **8 April 2019**_. *
    **Pascal**, calls for 2 reviewers once the next version is published. >
    **Action item**: **Yasuyuki Tanaka**, **Thomas Watteyne**, **Fabrice
    Theoleyre** to review new version of `draft-ietf-6tisch-msf` after Tengfei
    publishes it.  _Target deadline: **23 April 2019**_.
* _[12.03, expected 11.55]_ `draft-tiloca-6tisch-robust-scheduling` (**Marco
    * this draft is about an attack and its countermeasure. Attack is selective
    jamming, low-power and stealth. * As 6TiSCH is today, an attacker can learn
    the cell schedule easily and can launch a selective attack (already
    presented in Bangkok). * updates from -00 as a response of the
    questions/comments received in the previous IETF meeting * clarified
    adversary model. * Updated the key provisioning using the latest minimal
    security procedure * Need for reviews * **Thomas**: who read the draft? 10
    hands * **Thomas**: who's willing to review? > **Action item**: **Xavi
    Vilajosana**, **Tengfei Chang**, **Pascal Thubert** to review
    `draft-tiloca-6tisch-robust-scheduling`. _Target deadline: **25 April
* _[12:08]_ **Thomas**, we need to do some real-time reordering of the agenda.
    * Hackathon report will go last.
* _[12.08, expected 12.00]_ OpenBenchmark (**Bozidar Skrbic**)
    * Motivation, there are many papers that evaluate 6TiSCH, but fail to
    provide realistic operation scenarios * Desire for constant performance
    evaluation as the standard evolves: reliable tool to compare
    implementations * all experimentation should be based in tests scenarios.
    Try to mimic real world scenarios
        * SODA project.
        * Define KPIs
        * Environment and conditions/ configuration should mimic real scenarios
        * Expose REST API and GUI
        * Automated tests, continuous integration, etc.
    * 3 different scenarios: home / building / industrial automation
    * 3 platforms (Ghent, Inria Saclay, Inria Paris)
    * more info at https://benchmark.6tis.ch/
* _[12.13, expected 12.15]_ `draft-ietf-6tisch-dtsecurity-zerotouch-join`
(**Michael Richardson**)
    * Goal is to use protocols from other WGs.
    * BRSKI-19 responds to all WGLC requests
    * EST-COAPS document passed WGLC
    * EDHOC, no home for it. secdispatch interim was 2 weeks ago. No
    information about what is the progress on that direciton. * this parts are
    needed for a zerotouch document. * Looking for help/co-author. *
    **Malisa**: blocked by EDHOC. To decide if we go for DTLS path. * DTLS is
    too complex, packets are too long. Process is too slow. Trigs retransmit
    timers. * **Malisa**: Would be useful to have support from Security area
    and AD to progress in this work. * **Goran**: does not know results from
    secdispath. There will be news soon.
* _[12.13, expected 12.10]_ `draft-ietf-6tisch-enrollment-enhanced-beacon`
(**Michael Richardson**)
    * received comments
    * posted a new document
    * content of EB is stable. How much intro text is needed? how much is
    needed to motivate. * **Pascal**: review from the room and the WGLC. *
    Diego is going to do introductory text. Problem so far not well described.
    * **Pascal**: the ROLL document describes the problem. Just point at that.
* _[12.20, expected 12.05]_ Hackathon (**Tengfei Chang**, **Malisa Vucinic**)
    * Update about hackathon
    * OpenWSN+SODA Bechnmark
    * Benchmark server configures motes remotely, sends packets
    * implemented performance benchmark for MSF. Dashboard available online
    from the link provided in the slides. * see
* _[12.22, expected 12.20]_ Any Other Business
    * No time.
* _[12.23, expected 12.20]_ Meeting ends