Minutes interim-2020-core-06: Wed 16:00
minutes-interim-2020-core-06-202006101600-00

Meeting Minutes Constrained RESTful Environments (core) WG
Title Minutes interim-2020-core-06: Wed 16:00
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Last updated 2020-06-10

Meeting Minutes
minutes-interim-2020-core-06-202006101600

CoRE Virtual interim - 10-06-2020 - 14:00 UTC

Chairs:
* Marco Tiloca, RISE
* Jaime Jiménez, Ericsson

Material: https://datatracker.ietf.org/meeting/interim-2020-core-06/session/core
Webex: https://ietf.webex.com/ietf/j.php?MTID=ma4757116bab457defce5b14a9654c4e5

Minute takers: Thomas, Ivaylo, Marco and Jaime (helping)
Jabber scribes: Jaime

Participants:
1. Marco Tiloca, RISE
2. Jaime Jiménez, Ericsson
3. Jim Schaad, August Cellars
4. Jonathan Beri, startup
5. Thomas Fossati, arm
6. Klaus Hartke, Ericsson
7. Francesca Palombini, Ericsson
8. Ivaylo Petrov, Acklio
9. Rikard Höglund, RISE
10. Tim Costello, BT
11. Christian Amsüss
12. Peter Yee, AKAYLA
13. Mohamed Boucadair, Orange
14. David Navarro, IoTerop
15. Carsten Bormann, Uni Bremen TZI
16. Jon Shallow, ???
17.
18.
19.
20.

Note well presented.

* New blockwise and asynchronous non-traditional responses

   https://tools.ietf.org/html/draft-bosh-core-new-block-02

   - Relevant discussions on the list CoRE/DOTS discussions
       - https://mailarchive.ietf.org/arch/msg/core/H4NM0doO_ZzaHdkm5Op9UukP3-4/
       -
       https://mailarchive.ietf.org/arch/browse/core/?q=Review%20of%20draft-bosh-core-new-block-00

Jonathan presenting slides. Updates since -00.

Med: asking whether the text in 02 about congestion control is sufficient or not
Carsten: I haven't done any thorough analysis yet. But MAX_PAYLOADS == 10 is a
good way to start. We are doing congestion control in an environment that is
already congested (DDOS attack).

JonS: Block3 specific updates (slide 4-6)
Carsten: reviewed (on email) can we use the request tag option instead Block ID?
JonS: One of the things we thought about is having a block id on a separate
option. We would be changing the semantics on how block1 is used, superseding
it. At that point we decided to continue with Block3. CB: I was talking about
not changing the format of the option, rather than the option. JB: No issue
with that. Request Tag would work fine in principle. CB: Offline/email
discussion to happen with request tag. Moving into 64b space is something we
have tried to avoid it, it would be good to continue that. JonS: Agreed. CB:
there is no such thing as an "empty" token, not sure I can interpret the last
bullet on slide 4 JonS: token must have length. CB: 0 is a number, thus has
length (?) Med: we are assigning specific semantics to that Med: Carsten, to go
back a bit, we are registering option that is critical one and Request Tag is
defined as non-critical one, wouldn't that be an issue? CA: you can say that if
you implement Block3/4, then request tag has to be there, therefore making it
virtually critical CB: any reason why 4.18 as new response code? It used to be
a April's fools one. Bikeshed. JonS: understood. CA: is there any possibility
for the client to ask for an intermediate status request? things like "is this
good so far?" JonS: not an explicit signal CA: probably need an explcit one,
especially if going through proxies JonS: Block4 updates (slide 7-) CA: On the
ETag problem. Two situations: client sends etag to know if the representation
is fresh or wait for response that contains etag. Having bid (?) would be
useful when looking for historical representations. JonS: (TF -- sorry got
distracted couldn't grok this) CA: so, this is  about observation. If your
application needs to have every observation as a whole (historic data?) then
observation is not the tool. CB: if you do GET/FETCH and do the same you can
get back 2.03 and it's ok.  for methods which triggers results is a different
thing, and that's where you'd want the request tag to do the split. JonS: happy
with block 4 option split in two. We struggle with ETag, but did not consider
the representaiton of the observe. CB: We might want to have a loko at whether
the 24b sequence number is enough. JonS: 24b should be enough CA: Still
-reminding- it would not give you access to prev representations. JonS, MB: OK
not to use B4 tag as it is and make chances to use request tag instead. JonS:
WG Document, Adopt? CB: Adoption means that us a group have interest in working
on it, which seems the case. The other question, is whether we believe that
this is the approach we want here. During the development we see that there are
some bends and corners, still WIP but slowly converging. Still trying to
understand the implications on the ecosystem. JJ: is the adoption you need
urgently or can this wait a bit more?  I would like a full presentation of the
draft in one of the meetings, have some more discussion and further iteration. 
We have the WG pipeline already full at the moment. Med: We have a "DOTS
telemetry" document that depends on something like this (the dependency on this
would be normative).  Having adoption of the new block draft in the CoRE WG
would be a good signal in this direction. If we don't make progerss we won't
add dependency to teh blcok darft. We are open to integrate any the comments
from the CoRE WG. JJ: Even if it's immediately adopted we cannot guarantee how
much it'll take to finish the work. JJ: Proposal: present in July and after
that open the adoption call.  What other people think? CB: I don't see problems
adopting this work: the communication channel is in good shape and used in the
right way.  There is no risk to create damage in the CoAP ecosystem. Marco:
Med, you said previously that it could be possible to have an update later on
the telemetry work when things in CoRE are more stable. Is this still a vialbe
option? Med: Yes, although I would prefer to see this work advance quickly and
be able to use it in the DOTS telemetry spec. CA: What is its scope?  Is this
the successor of blockwise, a blockwise-bis? Or is it an extension for a
specific use case?  (In particular, with regards to the streaming mechanism
that was in -01.) Med: Agree and thank you for raising the comment. We wanted
something really focused that is why we removed teh streaming text. JJ:
blockwise-bis seems a bit ambitious given energy and WG items currently in
processing.  Trying to gauge the WG on this. JJ: present in July, scope it as
an extension (as opposed to blockwise-bis) and after that open the adoption
call. Med: we can use the mailing list to do the discussion before the meeting,
but really it's your call, whatever you suggest. JJ: I am worried that most
people have not read it for now and if we give people a bit more time, people
will be able to read it and have more feedback. Med: we will update the draft
to incorporate the feedback received today and notify the WG when we are ready.

---

coap.technology

Francesca: related to CoAP, not necessarily to the CoRE WG.  Carsten is
maintaining the site (https://coap.technology).  Added a "security" tab to the
web site.  PR is out
(https://github.com/coap-technology/coap-technology.github.io/pull/33).  I just
wanted to point this out. CB: want to put this up next week.  Need some
cleanup, rather hybrid situtation which I should fix.  For new PRs it's easier
to provide markdown.

---

OSCORE Groupcomm

Francesca: group OSCORE document update: new version due soon.  We did the
change to use the COSE "capabilities" column instead of our own registry. Jim:
I believe there is one hash alg already there, but I suppose you would never
use it. Jim: Oh, I guess I put that only in the key type. Francesca: Maybe in
the future there will be algorithms that register capabilities independent of
the key type. Jim: for the signature algorithm paratemer, just concatenate the
capabilities of the algorithm and the capabilities of the key type; do not
remove duplicate parameters

---

stateless status

Klaus: some points raised by Ben and Roman that I haven't yet addressed. All
other IESG comments seem resolved form his PoV.

---

Coreconf status

Ivaylo: Pushed new version of the SID document. Discussions ongoing in the list.
Carsten: Worth checking again about the SID vs. YSID naming.
Ivaylo: Also updated the COMI draft on Github. In no more comments come, this
can be the next version to publish.

---

Carsten: when is the next interim?
Marco: in 2 weeks, it's the last one before IETF 108
Christian: there I would like to present updates I am working on for the
Resource Directory