Subject: [6tisch] Minutes webex 20 December 2013

From: Thomas Watteyne <[email-masked]>
Date: Fri, 20 Dec 2013 11:10:39 -0800

All,

You will find the minutes of the last webex below.

FYI, all the minutes and slides are archived a
https://bitbucket.org/6tisch/meetings/.

Thanks to Xavi and Pascal for taking notes!

As usual, please fix anything we might have missed directly in the e-mail
and reply.

Thomas

 ----

Minutes Webex 20 December 2013, 6TiSCH WG

Note: timestamps in PST.
Taking notes *(using Etherpad)*

   1. Xavi Vilajosana
   2. Pascal Thubert
   3. Thomas Watteyne

Present *(alphabetically)*

   1. Alaeddine Weslati
   2. Cedric Adjih
   3. Diego Dujovne
   4. Giuseppe Piro
   5. Nicola Accettura
   6. Pascal Thubert
   7. Pat Kinney
   8. Pouria Zand
   9. Qin Wang
   10. Raghuram Sudhaakar
   11. Sedat Gormus
   12. Thomas Watteyne
   13. Tina Tsou
   14. Xavi Vilajosana

Recording

   - Webex recording (audio+slides,streaming)
   -
   https://cisco.webex.com/ciscosales/lsr.php?AT=pb&amp;SP=MC&amp;rID=73985697&amp;rKey=fef21ec3b4c68ddf<https://cisco.webex.com/ciscosales/lsr.php?AT=pb&SP=MC&rID=73985697&rKey=fef21ec3b4c68ddf>
    *[65min]*

Slides

   - slides_131220_webex.ppt<https://bitbucket.org/6tisch/meetings/src/master/131220_webex/slides_131220_webex.ppt>:
   slides shared during the call

Action Items

   - *Thomas* to send an email to the ML during the 2 next weeks to make
   clear that there is no meeting.
   - *Pascal* take "schedule" vs "slotframe" discussion to ML.
   - *Pascal* to detail use of chunks in architecture draft

Agenda

   - Administrivia *[2min]*
      - Approval agenda
      - Approval minutes last call
   - Definitions *[15min]*
      - cell
      - unscheduled cell
      - scheduled cell
      - to schedule a cell
      - broadcast cell
      - hard cell
      - soft cell
      - to reallocate a cell
      - chunk
      - chunk ownership delegation
      - chunk ownership appropriation
   - quick status update WIP drafts *[5min]*
      - draft-dujovne-6tisch-on-the-fly
      - draft-wang-6tisch-6top-interface
   - draft-piro-6tisch-security-issues-01.txt *[10min]*
   - AOB *[1min]*

Minutes

   - *[08.05]* Meeting starts
      - *Pascal* starts recording
      - [*Thomas*] This is the last call of the year. NO call in the next 2
      weeks (12/27 and 01/03).
   - Administrivia *[2min]*
      - Approval agenda

      No issues raised. Agenda approved.

      - Approval minutes last call

      No issues raised. minutes approved.

      - Last call of the year. No more calls during next two weeks.

      Action item: *Thomas* to send an email to the ML during the 2 next
      weeks to make clear that there is no meeting.

      - Maria Rita travelling, progressing terminology draft on her behalf.
      - list of terms to talk about are presented.
      - *Guissepe* will update us about the status of the security draft
      that was submitted earlier before IETF88 meeting in Vancouver
   - Definitions *[15min]*
      - cell

      A single element in the TSCH schedule, identified by a slotOffset, a
      channelOffset, a slotframeHandle. A cell can be scheduled or unscheduled.

      - updated to make it shorter and clearer.
         - *[Pascal]* The "schedule" is an abstraction owned by 6top.
         Should we replace "schedule" by "slotframe"? We refer to the matrix of
         cells.

         Action item: *Pascal* take "schedule" vs "slotframe" discussion to
         ML.

         - unscheduled cell

      A cell which is not used by the IEEE802.15.4e TSCH implementation.

      - *[Pascal]* Term "cell" is used for an entry in the matrix and at
         some point is used to identify the unit of transmission.
         - *[Pascal]* Unit of transmission, we should agree either we use
         this abuse of notation or not.
      - scheduled cell

      A cell which is assigned a neighbor MAC address (possible the
      broadcast address), and one or more of the following flags: TX,
RX, shared,
      timeskeeping. A scheduled cell can be used by the IEEE802.15.4e TSCH
      implementation to communicate. A scheduled cell can be a hard cell or a
      soft cell.

      - removed"hard" flag as this is part of 6top and not part of the
         cell. What is hard or soft is the unit of transmission, not
the cell itself.
         - Unit of transmission seems a good candidate to describe the use
         of a cell and separate from cell (container). The term "unit of
         transmission" can be changed in a future.
      - to schedule a cell

      The action of turning an unscheduled cell into a scheduled cell.

      - broadcast cell

      a scheduled cell with neighbor MAC address the broadcast address.

      - hard cell

      A scheduled cell which the 6top sublayer cannot reallocate.

      - soft cell

      A scheduled cell which the 6top sublayer can reallocate.

      - to reallocate a cell

      the action by the 6top sublayer of changing the slotOffset and/or
      channelOffset of a soft cell.

      - *[Thomas]* is relocate (as now it is unit of transmission)?
      - chunk:

      a well-known list of non-contiguous (i.e., well-distributed in time
      and frequency) cells within a slotframe; a chunk represents a
portion of a
      slotframe that can be managed separately by an individual node.
Chunks can
      be pre-programmed, or can be computed by the PCE when the network
      bootstraps.

      - *[Thomas]* Non-contiguous seem not correct. They can be contiguous.
         So recommends removing from definition.
         - *[Thomas]* State also that the way chunks are allocated is out
         of the scope.
         - *[Thomas]* Missing the concept of identifier of the chunk.
         - *[Pascal]* Remove the last sentence and reword so that the
         meaning of the sentence indicates that the chunk is global
and known by
         everyone.
         - *[Diego]* Do we allow overlap of different chunks?
         - *[Pascal]* Yes.
         - *[Qin]* How do nodes that own different chunks communicate?
         - *[Pascal]* A node can have multiple chunks. And can use them
         according to a policy. Important to know if chunks are
overlapping or not.

         Action item: *Pascal* to detail use of chunks in architecture draft

         - chunk ownership delegation

      The process by which an individual node obtains a chunk to manage
      based on point-to-point interaction with a PCE.

      - *[Thomas]* Not use the PCE as an example, generalize to external
         entity.
      - chunk ownership appropriation:

      The process by which an individual node obtains a chunk to manage
      based on peer-to-peer interaction with its neighbors

      - *[Thomas]* we need to skip detailing in the description specific
         methods (e.g PCE)
         - *[Pascal]* delegation multiple hops away a cell is allocated,
         appropriation is one hop, no owner but by means of negotiation
         - *[Qin]* it seems very similar to 6top negotiation.
         - *[Pascal]* unit of tx between A and B and 6top in A negotiates
         with 6top in B (schedule time frame).
         - *[Pascal]* A chunk delegation or appropriation is a boot-time
         thing (or a ramp-up thing). The idea is to allocate some
chunks (set of
         cells) to be used to allocate particular units of transmission.
         - *[Thomas]* the mechanism itself (only mechanism) seems very
         close to 6top negotiation mechanism.
         - *[Qin]* 6top-to-6top should support ownership appropriation?
         - *[Thomas]* the 6top interface should have the methods to
         manipulate chunks as it has now methods to manipulate soft cells.
         - *[Qin]* we need to define some specific mechanism to support
         that and this is almost identical to soft cell negotiation.
         - *[Pascal]* the difference is that the chunk negotiation is
         broadcast, one node to all neighbors to indicate the presence
of a chunk
      - *[08:51]* Quick status update WIP drafts *[5min]*
      - draft-dujovne-6tisch-on-the-fly
         - *Diego* speaks about 10 issues logged in issue tracker
         - other issues not update in the slide.
         -
         https://bitbucket.org/6tisch/draft-dujovne-6tisch-on-the-fly/issues?status=new&amp;status=open<https://bitbucket.org/6tisch/draft-dujovne-6tisch-on-the-fly/issues?status=new&status=open>
has
         the issues tracked in bitbucket since this is a personal submission.
         - *Thomas* suggest to group issues a bit more to limit the overhead
         - *[Diego]* Should be CC ML on all issue updates?
         - *[Thomas]* Maybe. Thoughts?
         - *[Pascal]* better to not have issue notification to the ML for
         non-working group documents.
      - draft-wang-6tisch-6top-interface
         - *[Qin]* we need to define the MIB tables defining the content of
         the 6top layer. This is an intermediate step to achieve a useful yang
         model. The real format is not important for that tables as
they will not
         appear in the draft.
      - draft-piro-6tisch-security-issues-01.txt *[10min]*
      - new version submitted.
      - the new document takes the feedback received from the ML into
      account.
      - use 6top layer to build the secure context. 6top and MAC interact
      using the commands defined in 6top draft.
      - *[Thomas]* Call for reviewers for this security drafts.

      Action item: *Thomas* to call for reviewers of
      draft-piro-6tisch-security-issues-01.txt on ML.

      - draft-richardson-6tisch-security-architecture-00
      - Michael Richardson submitted a new draft on security, the draft
      will evolve as discussions evolve.
      - goal is not a solution draft but a high level architecture. *9:07
      AOB *[1min]*
      - next meeting will be the 10th of January.
      - happy holidays!
   - *[09.10]* Meeting ends