Minutes interim-2020-lpwan-02: Wed 16:00
minutes-interim-2020-lpwan-02-202001221600-00

Connection details
------------------
• Date: 7-8am US Pacific, 4pm CET:
https://www.worldtimebuddy.com/?qm=1&lid=100,12,5392171,1850147&h=100&date=2020-01-22&sln=15-16
Meeting link:
https://cisco.webex.com/cisco/j.php?MTID=me91d56b37454056b8c5ef3b102b9da50
Meeting number: 201 266 501 Password: txCGJTrS (89245877 from phones)

Agenda
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[16:05] Administrivia                [ 5min]
    o    Note-Well, Scribes, Agenda Bashing
    o    Status of drafts

[16:10] SCHC Yang Data Model (Laurent)   [15min]
[16:25] SCHC over PPP (Pascal)                [15min]
[16:40] SCHC CoAP (Ana)                           [ 5min]
[16:45] SCHC over LoRaWAN (Olivier)       [ 5min]
[16:50] OpenSCHC (TBD)                            [ 5min]
[16:55] AOB                                                 [ 5min]

Minutes takers
-------------------
Ana Minaburo
Pascal Thubert
Arunprabhu Kandasamy
Laurent
Dominique

Attendees
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 - Alexander Pelov
 - Ana Minaburo
 - Laurent Toutain
 - Carles Gomez
 - Julien Catalano
 - Pascal Thubert
 - Ivaylo Petrov
 - Dominique Barthel
 - Olivier Gimenez
 - Vincent Audebert
 - Juan Carlos Zuniga
 - Arunprabhu Kandasamy
 - Diego Dujovne

Missing Past Attendees
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Meeting minutes
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[16:07] Administrivia                [ 5min]
    o    Note-Well, Scribes, Agenda Bashing
    o    Status of drafts
AP: Gives the Note well
AP: Agenda is accepted
AP: Minutes from last meetings are accepted
AP: Sent a mail to Eric and Suresh to see the status of SCHC-24 and CoAP-12
Pascal Thubert: Responsible AD is now Eric Vincke.
Alex reminds of meeting request, early-brid registration cutoff, draft
submission deadline.

[16:12] SCHC Yang Data Model (Laurent)   [15min]
Laurent: short update, focussing on one topic. Representation of TV: numerical
will be of type "binary", no limit on size. Ivo: seems good It is possible to
enforce the maximum size. TBD check for teh capability to do a union with the
string and position representations. Alexander: If there is union with several
types the SID is for the union. It can be inconvenient. It might be more
efficient in cases to avoid union though here it should be OK. Laurent: we have
agrouping and inside the grouping we have a union. Alex: It is not only about
is the model correct but also about protecting the future against ambiguity. Do
a model that is correct without caring for efficiency, then we lk at the
efficiency of the encoding. Alex: the reason union can be somewhat less
efficient on the wire with CORECONF is because YANG-DATA needs to be serialized
without any ambiduity to CBOR and the other way around. ACtION ITEM: Ivaylo and
Alex - check the union serialization with SIDs. Laurent: will check with Yang
doctor LT: WE need something that is efficient in yang, in Cbor and coreconf in
order to do not change the actual drafts

[16:24] SCHC-over-PPP (Pascal)           [15min]
Pascal: The idea was to use SCHC over foo and then define it over PPP that
brings the serial links. PPP give us naturally SCHC over Ehternet with PPPoE.
the cost is very limited RFC5172 that define how to do negotiate RoHC over PPP
and this draft is only to complete the serie and have SCHC on PPP Laurent: MTU
negociation in PPP? Pascal will check. Pascal: what to do with this draft?
Alex: would love to see this become a WG item, but will talk to the ADs and see
if rechartering is needed. Pascal: last time, said we would progress the draft
within LPWAN and forward it to IntArea later. JCZ: use case? Pascal; smaller
blocks in WiFi6, better control loops in industrial/smargrid situations.
Laurent, Dominique willing to contribute to IntArea. Alex: 107 or later?
Pascal: no reason to wait. Could have a presentation at IntArea. Laurent: good
to educate IntArea soon, since we might be requesting codepoints for OAM, etc.
The better they know SCHC, the easier. Diego: why SCHC over PPP and not
directly over L2 technology. Does not PPP introduce an overhead? Pascal: good
point. Will add a section on why PPP.
 Can't do SCHC over Ethernet, unless get a new Ethertype. With PPP as a
 middle-protocol, this is solved.
Diego: OAM draft currently only considered LPWANs, with this draft, scope of
OAM made wider? Pascal: device could be asleep, even if link is Wifi or
Ethernet. Common basis of the OAM work.

Pascal todo: use cases on why needed outside LPWAN. Why PPP overhead?. Discuss
also low power devices over Wi-Fi.

[16:43] SCHC CoAP (Ana)                  [ 5min]
One review has been received from iotdir, asked to add a part to say what to do
if no valid rule are found. Ana made the change. waiting from Tim Chown
comments INTAREA.

Ana: do we send a mail to Tim Chown to speed up his review ?
Pascal: send gentle reminder.
Dominique: Tim has not reviewed the generic SCHC draft.
Ana: Will probably take him some time to read the SCHC draft before being able
to review SCHC Coap.

[16:48] SCHC-over-LoRaWAN (Olivier)      [ 5min]
changes in draft-05
    - added IID proposition with appskey
    - thanks to Dominique for review
    - ack behaviour changed

    IID proposal. Still under discussion at the Lora Alliance, will likely
    accept to use appskey to compute IID, in the future a new key will be added
    in the LoRaWAN standard.
LoRa Alliance meeting next week. Will be opportunity to discuss with LoRa
Allaince members and get a closure on this topic. Pending items - Inactivity
timer issue, talk with Arun,

If the last issue is solved, then go to a last call

Dominique: collision issue in IID, with birthday paradoxe, the collision
propability may be greater than expected. JCZ: this dicussion already held in
2014-2015 at IEEE. Main problem was DHCP table size, privacy issues, not
collision. Julien: doing a re-join means losing all state associated with the
link. Don't recomment to do a rejoin just to generate a new AppSKey. Julien:
RFC7217, no great guidance. Pascal: will "never" happen, we only need to say
what we can do (even if not nice) if it were to happen.

[16:50] OpenSCHC (TBD)                   [ 5min]

next time

[16:55] AOB                              [ 5min]