draft-ietf-core-links-json-10 and draft-ietf-core-cocoa-03 are in IESG processing and are awaiting new versions from the authors. Side meetings at this meeting have made progress addressing some of the open issues from AD and IESG input.
draft-ietf-core-object-security-13 is in IESG processing and is waiting for a review from Eric Rescorla, with a view to Eric clearing the remaining DISCUSS held on the document. Technical Changes resulting from IESG and directorate inputs were discussed. Responsible AD Alexey triggered a second IETF last call to cover those changes.
draft-ietf-core-oscore-groupcomm-02 is nearing WG last call. The plan is to progress this independently from the related ACE documents as the membership and group key management can be done by other means (e.g., using a simple REST API). Before the WGLC another interop should be held (implementation draft then to be published based on outcome of the processing of basic OSCORE).
draft-ietf-core-echo-request-tag-02 requires a few more reviews; no formal dependency but it would be good to finish this approximately on the same timeline as OSCORE.
draft-ietf-core-resource-directory-14 was discussed, with some focus of the semantics of the incoming (registration) and outgoing (lookup) links. With several implementations becoming available An interop would be next; September/early October time frame is envisioned. Next step then could be WGLC.
draft-ietf-core-rd-dns-sd-02 was discussed (and later presented in DNSSD WG as well). Much of the discussion centered about how the rt= target attribute can be turned into a service type on the DNSSD side. (Later in the DNSSD meeting, the question came up whether that is the right pairing in the first place.) All DNSSD service types must be registered (15 ldh characters max); CoRE resource types can be registered (63 characters max) or can be URIs. Further work on this is needed, as is on the pairing of ins= and DNSSD instance identifiers.
The CoRECONF cluster (new old name for yang-cbor draft-ietf-core-yang-cbor-06, comi draft-ietf-core-comi-03, and sid draft-ietf-core-sid-04) has recently received reviews fro the netmod community; a few more from the CoRE side and maybe another interop would be good before WGLC of this cluster, envisioned to close before IETF103. draft-veillette-core-yang-library has a little more time. As a major technical change it was agreed to always start a yang-cbor tree with a SID delta base of 0. This has slight performance disadvantages, but makes handling the payloads much less error-prone.
The CoRE WG is not the place to develop YANG modules that match this functionality. A group will initiate the steps toward a new WG, tentatively called Yang Of Things (yot).
draft-ietf-core-dev-urn-02 was presented, with a focus on the small changes needed for alignment with OMA LWM2M. There was some support for this alignment in the room. Jari Arkko will coordinate with OMA and report back.
(end of Monday meeting)
draft-ietf-core-senml-16 is in AUTH48 as of 2018-07-19, RFC-to-be 8428.
A quick heads up from Roman Danyliw pointed to the 2nd WGLC of DOTS signaling draft-ietf-dots-signal-channel-21, which uses CoAP. Interested reviewers were found.
draft-keranen-core-senml-fetch-01 found a few reviewers. Interest to be confirmed on the mailing list, in the case of success followed by a call for WG adaption.
A procedural point about IANA registering of SenML fields was discussed. If a registrant is not interested in EXI, no attempt should be made to register a new XML/EXI schema name. Authors to check with IANA whether the schema could be stored with the registration. As the first exercise of the registry went less than perfectly, AUTH48 to be used to add a couple of clarifying sentences.
For stateless forward proxies, there was good interest to explore the option of introducing an extended token. The plan is to realize (WGLC) or dismiss (revert to separate option, now also called Extended Token) before Bangkok.
draft-ietf-core-too-many-reqs-02 has passed WGLC. Authors will fix typos and then publication will be requested (instead of a second WGLC we will use the IETF last call for any emerging WG comments).
draft-ietf-core-multipart-ct-01 is ready for WGLC. As thw WG tends to think this will be successful, early registration of the Content-Format codepoint will now be pursued (following the procedure for this).
draft-bormann-core-proactive-ct-00 received good support. Next step is WG adoption call on mailing list.
The second meeting ran over time significantly. The remaining items on the agenda, CoRE interfaces, dynlink, pubsub, and protocol negotiation, as well as presentation and discussion of draft-jarvinen-core-fasor-00, will move to interim meetings.
--------------------- ╔═╗┌─┐╦═╗╔═╗ ╦ ╦╔═╗ ║ │ │╠╦╝║╣ ║║║║ ╦ ╚═╝└─┘╩╚═╚═╝ ╚╩╝╚═╝ --------------------- Core@IETF102 Constrained RESTful Environments WG Chairs (firstname.lastname@example.org): Jaime Jiménez Carsten Bormann Minute Takers: Ludwig Seitz, Ana Minaburo, Christer Holmberg, Ari Keränen, Francesca Thank you! Slides !(https://datatracker.ietf.org/meeting/102/materials/slides-102-core-consolidated-slides-03.pdf) Meetecho http://www.meetecho.com/ietf102/core # MONDAY, July 16, 2018 **1550–1750 Duluth** ## Intro (10) * WG and document status * In RFC editor queue: draft-ietf-core-senml-16 * Quick recap of related work, pointers CB: Patents needs to be known, new version of Note Well CB: DNSSD Thu 9.30-12.00 Duluth, OCF/T2TRG coordination call Wed 11..12 (ask chairs) ### In IESG processing: * Document status only (IESG Processing): * draft-ietf-core-links-json-10 2018-02-26 Waiting for AD Go-Ahead::Revised I-D Needed CB: Did refocussing after extensive feedback in IESG, still ongoing * Document status, pointer to new work * draft-ietf-core-cocoa-03 2018-02-21 AD Evaluation CB: Great TSV AD feedback, need to process. Carles has produced already a PR. CB: Core WG does not expect to have a single Congestion Control Christer Holmberg: Provided a review for the document. Carles: The updates with his feedback are already in a PR, we should have captured your feedback there. * Related work: draft-jarvinen-core-fasor-00 new 2018-07-02 ➔ Thu CB: To be discussed on Thu if time ## OSCORE cluster (40) * draft-ietf-core-object-security-13 2018-06-27 IESG Evaluation::AD Followup Göran Presenting. Now in version 13 Main changes: Clarifications based on IESG reviews, Appendix D: overview of Security properties Add protection for some options, Additional clarifications and simplifications. Comments are linked to the IESG review Wiki contains explanations about how reviews were addressed Previously Observe was entirely an outer option but no it's an inner option which enables endpoints to verifies each others intent Separated out Observe and Blockwise processing to simplify description. NoResponse option now essentially inner New subsection on URI-Host/Port processing Updates on HTTP processing based on Martin Thomson's comments New parameter called ID context, to transport context information to retrive the security context Updated deployment examples and test vectors Next steps: Updates based on new review comments Continue IESG evaluation Interop-testing new version CB: Who has read this version of this draft? (Answer: 2) Alexey: Lots of good changes, sections moved around -> not easy to diff . To do IETF Last Call this week, will happen while Ekr is reviewing the last version of the draft. Will try to start this week. * draft-ietf-core-oscore-groupcomm-02 new 2018-06-28 Active Marco presenting Major revision based on discussions at IETF101 Updates from -01 Revised terminology Group Id stored in new parameter Context Id Format of external_aad aligned with OSCORE Security considerations section has 2 new subsections: first is on uniqueness of key and second on collision of group identifiers Appendix C Example of Group Id format, discourage collisions Appendix D.2 provisioning/retrieval public keys Implementations: Java version based on CF planned OSRAM in C Contiki OS PoC need to be aligned with latest versions Related Activity: joining an oscore group using the ACE framework renaming for consistency CB: We are finishing other docs now dealing with groups, eg RD has a way to handle groups. Does this fit together in any way? Peter vdS: Some work should be done given the work in the RD JimS: Do not believe there is overlap. Who is managing groups in RD? The party doing the management in RD and here should be the same, however that is being defined in ACE. CB: Who wants to do the job Peter suggested? PvdS: Will contribute, also Michael Koster and Jim Schaad. CB: most likely 3 docs that work together to do this would be in a cluster. What is the relative speed for finishing this? Jim: Not expecting the docs in ACE to go anywhere before next summer, how much does this doc rely on those docs? Marco: Think we can progress independently CB: Using this without ACE requires some other form of management of keys Jim: if willing to do static config, no (dynamic rekeying necessary?) CB: Who has read a recent version? (5 hands). Who would be reviewing: Peter, Jim, Bill, Michael. GS: Volunteers please have a look first to OSCoRE. CB: Do the authors believe this is ready for WGLC? GS: Interop test would be nice. CB: Is the current draft the implementation draft? FP: We could wait for the update on OSCORE before the interop. Process reviews for v13 and IETFLC * draft-ietf-core-echo-request-tag-02 new 2018-06-29 Active GS: Would be good to have more reviews on that, related to security CB: Who has read a recent version? (answer: 6) GS: (on EDHOC) We updated it, key-exchange protocol for OSCORE, have formal verification on last version, reduction of message sizes 1/2 for RPK and 1/3 for PSK compared to DTLS CB: One more review cycle to be done. ## Resource directory cluster (40) * draft-ietf-core-resource-directory-14 new 2018-07-02 Active Peter vdS presenting Gives the improvements to the URI section explain how to get from reference to target URI Link semantics from host to RD to the resolution of the absolute target Registration Base URI RFC6690 and RFC8288 anchors and URIs Other improvements (renaming, clarifications) TODO react to reviews, some ambiguous text left, time for WGLC Jim: Don't think WGLC is good before interop. CB: Did start interop testing. CB: Who has an RD implementation? (4-5 hands) Acklio, Matthias, Jim, CB CB: Set something up during September for interop, convenient? * draft-ietf-core-rd-dns-sd-02 new 2018-07-02 Active Kerry Lynn presenting Hoping for co-authors from DNSSD KL: How many people have read the draft (two hands). Why? We should be able to interop between RD and DNS services Granularity of DNS is larger so that can be used to drill in to find out exact services needed Who knows how DNS works? (most hands raised). Short overview of DNS-based service discovery New Link Target Attributes exp is currently defined as a binary ins is globally unique across devices of this type may need to generate service types from the rt Link-format 2 DNS-SD mapping Example mapping Please follow up proposals you make on the list, we will spend more cycles on this now Dave Thaler: That string (_oic) must be IANA registered Stuart Cheshire: DNS-SD designed for constrained, CoRE as well but allows much more verbose content DT: The discussion is on the _oic field. if _oic must be iana registered what is the process to deriving the rest. CB: General comment: Seeing situations with different IANA regs that need to be synced. May be how we can handel this here as well ... How should the hierarchy be used? Needs thinking. If people have ideas, please comment on the mailing list KL: <Notetaker: too fast, didn't capture> SC: Quick comment on the hierarchy. When we did DNS-SD we settled on a very limited hierarchy with types and subtypes but not deep nested hierarchies. Hierarchy is useful when software access it at different points. Hard to find an app that would use a collection of devices when they have nothing in common (notetaker: i.e. printer and toaster.) KL: May have additional problem: CoAP used to be about UDP, now we need to express everything else, may need to expand the # of labels in service part to express more complete bindings CB: Second SCs comments on restricting hierarchies Matthias Kovatsch: Issue with (discussed on ML) ins attribute, originally used to distinguish resource with similar rt. With redefinition we lost that capability, need to rethink framework to solve this problem, good that definition is clear now, but need the lost functionality KL: Scope of the end point KL: People using things before they are defined, need to go back and define them MK: Need has been there all along, need to go back and fill gap CB: Not much feedback on ML because messy to clean up KL: Mapping from free-form environment now vs specific constraints in DNS-SD, should we become more specific? MK: It is also fine to define it as it is. Implementations will have to change as they are not interoperable. SC: Question, didn't understand example (MKs). How is this different form other instance names MK: Need to know to whom the device belongs (a hierarchical) SC: How is this done today? MK: Hierarchies SC: Written down? MK: Was in early versions of interface draft, also used in web linking, need to write it down (again) to make it clear SC: Need way to diff instances in RD DT: OCF doesn't use it but RFC 6690 allows arbitrary values in rt values, is there a way to map them? RFC6690 KL: Did not consider KL: Not many rt registered in IANA as of today. Only OIC. Michael K: I wouldn't assume that no registration means no existance. DT and CB: By definition there is no need to register them, there are two options there. ## CoRECONF cluster (15) Carsten gives exposition: SNMP => Netconf + YANG HTTP + html + json = RESTCONF CoAP + cbor + sid + yang = CoRECONF Document called COMI and bundle called COMI -> confusing Now called CoRECONF to reduce confusion Alexander Pelov presenting * draft-ietf-core-yang-cbor-06 2018-02-08 Active (discuss observations from active use, NMDA) * draft-ietf-core-comi-03 2018-06-04 Active * draft-ietf-core-sid-04 2018-06-04 Active * draft-veillette-core-yang-library-02 2018-01-24 The status of the different drafts that are almost ready for WGLC after the inputs of today Next slide: Different protocol stacks What we have today: example SID registry, implementations, 3 hackathons Hackathon 102: supposed to be achieved: Open source python examples, implementation and documentation what was achieved: base examples, COMI client implementation started CISCO has Yang DK that allows to generate examples in C, Python and Go. YANG-CBOR + SID was reviewed comment related to delta-encoding Include the encoding in the payload to reduce ambiguities Proposed change to help debugging but adds overhead CB: There was no ambiguitty in the existing proposal but we missed a requirement, the one to rip the payload out of the context and do somehting usefull with it. It is important to fullfill it. On the specific example, you would compress the dates there. Thinks that's a valid comment Dave Robin: on other protocols there is a similar situation. We used tagging, adding an attribute called "self" which was the URI of the context. On the wire is redundant, it is only used when handing the informaiton to someone else. Henk B.: Think this is similar, do /p for payload. Do <too fast didn't get that> and problem goes away. CB: No exactly same problem AP: We need to discuss to see how to get this requirement CB: Hard to make sure the transformation always happens. Need to figure out details. Other results: # of media types goes down, the differ on how we use context, less if we use less context AP: This is for COMI type, the YANG and CBOR is different. Please give feedback on the mailing list. Laurent Toutain: on constrained network use the restricted format and extend it through the cbor-template AP: Conclusion Yang-CBOR + SID ready, same for COMI, next steps: Hackathon, BOF for Yang of Things CB: WGLC during September, after interop is done. HB: Notion of Netconf notiff(?) drafts modular wrt transports, need to align with Netconf CB: Would write this draft with content "look there". Wouldn't want to destabilize the well-ripened (sic!) documents. The YANG library need to be included in this cluster Is nimda damaging your document? (question to Michel Veillette) MV: Next step WG adoption HB: <didn't capture> AP: This could be the place for Yang of Things (YoT) for communities to meet CB: Want to talk about YoT? AP: Had side meeting several IETF ago. If there is CoREConf there will be modules usable for IoT. There was a lot of interest at the time. CB: On Thu a CoAP customer will present how CoAP is used for DDOS detection (DOT WG). Concise YANG Telemetry (draft-birkholz-yang-core-telemetry, ) Henk B: Short intro on Concise YANG telemetry 2 drafts: subscribe notifications and yang push ## SenML cluster (15) * draft-ietf-core-dev-urn-02 new 2018-07-02 Active * (discuss in proximity to RD endpoint naming issue) draft-ietf- core-dev-urn-02 Jari Arkko presenting Version -02 aligning: with OMA LwM2M 3 levels of "private" device ids Questions: Do we agree to align with OMA? OMA uses OUIs we use PENs, which should we use? Does this affect use of org/os/ops? Jaime Jimenez: OMA perspective: Ok with PEN, unification OK. Most common URN usage is IMEI (rather than dev:urn). JA: Could this be discussed in OMA? JJ: Since in IETF there are quite a few OMA members we could discuss this. Kerry Lynn: When you use "private" you are not talking about privacy? JA: There are cases where that makes sense, want to enable ??? Ari Keranen: In SENML we recommend URN as solution dev:urn. Concerned about adding person sign (?) would make this only semi-compatible AK: Good agenda point for OMA coord. Padhu S: Several evolving URN formats. Generalized here with one format would be useful. CB: What is next step? JA: Need to coordinate with OMA, will try and report back Σ 120 # THURSDAY, July 19, 2018 **1810–1910 Van Horne** ## Intro (5) * draft-ietf-core-senml-16 2018-05-18 RFC Ed Queue SenML in AUTH48! RFC8428! * F-INTEROP F-interop https://go.f-interop.eu/ ## DOTS (updated agenda) * draft-ietf-dots-signal-channel-21 Using CoAP for DDOS mitigation signaling. Standardize the messages/communication from a system under attack to ask for mitigation help. Asking for help: CoAP protocol doc in 2nd WGLC. Would like to have expert reviews. Please review within the next 2 weeks: DOTS Signal Channel document Dave T, Bill S, Jaime J, interested to have a look at this. ## (Any spillover) (0) ## FETCH and PATCH for SenML * draft-keranen-core-senml-fetch-01 new 2018-07-02 Ari presents changes since -00 Add/Append/Replace/Delete with (i)PATCH: Delete is new. Concluded there is no need for op-codes. Adding time needs two operations. 3 T.B.D.s Ari asks for WG adoption. 4 read a version Reviews to be done by Michael Koster, Bill, Carsten Some hands for doing this. No hands against doing this. Confirm on the mailing list for interest, and then (possibly) adoption call ## IANA registry maintenance for SenML XML Schema needs to be changed and renmed when adding a new entry. Bad for EXI, which needs the Schema for (de)serialization. proposal: clarify that you don't have to register schema, but if someone needs it, they can register all those needed Jim Schaad: Would like to see that you don't have to add several field in order to register the schema. Alexey: do you really want to publish EXI in the current doc (AUTH48)? Ari Keranen: Let's publish this, this does not need to update the document. It has to do more with the registry. Carsten: maybe this is more about creating awareness. AK: Latest request for LwM2M "vlo" shoud be fine. No need to change rfc. (LWM2M thing should be fine) All the schema could be somewhere like a wiki, but don't need to be in RFC. Alexey: will you need new mediatype for EXI schema? Carsten: no Alexey: not totally confident about EXI nor changes. Would you have a draft describing this? CB: It's all in the SenML draft already AK: yes everythig we are discussing is already in the doc, maybe just clarifying. ## Related work in other WGs (15) ### Stateless Forward Proxies * draft-ietf-6tisch-minimal-security-06 (discuss stateless) Problem statement: Normally proxy fw the request. and while it waits for the response, it has to keep state in 6tisch, proxy is very constrained Idea: forward the state to the origin server and receive it back with the response. Question: what is the best way to do this? This could go into the token, which was defined with this behavior, but unfortunately limited to 8 bytes. Using a token option introduces a second token, which is ugly. Could use reserved values for the token length for option length encoding. This would work for 6TiSCH, but would break generic deployed CoAP implementations. (like for options) It would need all intermedaries to understand this mechanism. Should do the right thing way too late or do a thing that is not quite right. Would need to write a draft that updates RFC7252 and 8323. Dave Thaler: decent idea. Not clear of caveat slide (9). Are you assuming the client (and intermediaries acting as clients) are allowed to do stateful and stateless? Carsten: implementation would keep in practice one state. Tries to do stateless thing once but keeps the state to handle errors. Dave: rest may be worth doing, this I am more scheptical. Intermediary as client. Others may come in. Need to wrap in anyway. Queue length of 1 has problem with intermediaries. Carsten: doing this without support is not catastrophic Dave: would rather keep simple. If client asks for stateless one and who path doesn't support, you get error/failure. Carsten: problem is you would not have way to tell; what do you do with proxy 1 Dave: that's where you lost me. Carsten: fw proxy knows nothing about where the message comes from Dave: slide is under-specified; have to deal with path changes in middle of things. Carsten: Fw proxy, so every proxy is aware of the next hop Dave: can change but you just know when they changed Dave Robin: what is the short red line on the client (sl 9)? Carsten: token goes to ultimate server, proxy 3 can keep state Dave R: there is no alternative, I don't like this. Extra token works in all places? Carsten: no you are in the same situation, beause the proxy does not support the option Dave: tokens are not safe to forward but are forwarded? Carsten: safe to forward *when you dont know what it means*. Safe to forward bit to indicate if elective for proxy to understand. Dave R: seems layering is the safer version even if it takes more space. Involved in very similar discussion earlier. Carsten: proposal (sl ?) <- we know this is the right way to do it, but ... (missed it) Carsten: Klaus proposes: write this up. (in particular explain slide 9) Needs to be done by BKK. Dave R: not being able to not recover at all is bad. You have one or two slots for state. If can't do stateless because next doesn't. You start dropping stuff. In few minutes could work. But in this refuse to keep any state and will not get the message. Carsten: yes with the amendment you keep one state, you know it will work. Dave T: is there a case for client to need a token larger than 8? Carsten: the client might be in the same situation. Dave: sounds like answer is: when CoAP client is acting as intermediary. Carsten: which most devices do Matthias: What about NSTART=1? To send multiple request (NSTART>1), the client needs CoCoA or similar. In this case we do not talk about highly constrained devices that must be stateless. Conversely, with NSTART=1, we should be able to expect the client to store the state for this one open request. Carsten: good question; but think we have this covered. Sympathy in the room that it is worth for authors to write this up. Has to be done quickly. Who would be willing and able to review? August time frame: - Peter vdS, Jim, Dave R. ## Housekeeping cluster (12) ### Too Many Requests response code for CoAP * draft-ietf-core-too-many-reqs-02 new 2018-07-02 Active Presenting the changes since IETF101 (see slides) Carsten: we should not delay this unnecessarily. Can we do WGLC? Ari: we did, ended today Carsten: do we need another one? Ari: very similar version. One update to fix the typo but after that we are ready to go forward. Peter van der Stok: the related is not very clear to me. Ari: it would be up to the application to have that knowledge. you would not have to use this similar method at all, only for the application it would make sense. in the current spec we cannot define what is "similar enough" Peter: ok Carsten: fix the typo, then chairs ship to IESG. (there is still the IETF LC) Anybody have a problem with that? No rejection from the room ### Multipart * draft-ietf-core-multipart-ct-01 new 2018-07-02 Active Replaces a number of proposals including Maybe. Needed for EST over CoAP. Time for WGLC? Objections? Peter vd Stok: very much in favor for WGLC. Would like to do a request for early registration for content formats Carsten: there is a procedure and we just follow it Alexey: just follow procedure? Jim: are you going to ask something 0-255? then you don't need early registration, just ask AD. Over 255 needs early reg. Assumption: WG think this doc will happen. ### Proactive * draft-bormann-core-proactive-ct-00 new 2018-07-02 Should start registering all sensible available media types. With less than 2000 media types and 64k code points, we can "waste" some. Alexey: what problem trying to address? Carsten: the threshold. Person needs to exercise a process they don't understand. Ari: it makes sense Matthias: didnt have the time to read the draft, but followed the discussion and repeatedly had the problem of missing Content-Format numbers. Jaime: anybody have a particular problem with adopting this? No objections Jaime: we will do mailing list poll Carsten: missed many presentations. Will start virtual interims. # End of meeting (out of time) ## Active (14): * draft-ietf-core-coap-pubsub-05 new 2018-07-02 Active * draft-ietf-core-dynlink-06 new 2018-07-02 Active * draft-ietf-core-interfaces-12 2018-06-26 Active * draft-silverajan-core-coap-alternative-transports-11 2018-03-05 * draft-silverajan-core-coap-protocol-negotiation-09 new 2018-07-02 (what is needed to be ready for WG adoption?) ## New work: Congestion control, continued (14) * draft-jarvinen-core-fasor-00 new 2018-07-02 Σ 60 # No Agenda time in IETF 102 ## Not discussed this time: * draft-birkholz-core-coid -00 new 2018-07-02 * draft-dorfner-core-simplemetadata -00 2018-04-16 * draft-urien-core-blockchain-transaction-protocol -00 2018-03-02 * draft-urien-core-identity-module-coap -04 2018-06-25 * draft-urien-core-racs -11 2018-06-12 ## Last IETF: * draft-wang-core-opcua-transmission -03 2018-03-03 * draft-mattsson-core-coap-actuators -05 2018-03-20 * draft-bormann-core-ace-aif -05 2018-01-18 * draft-amsuess-core-rd-replication -01 2018-03-02 ## Replaced by other drafts: * draft-hartke-core-pending -02 2018-02-26