22 May 2015 Webex IPv6 over the TSCH mode of IEEE 802.15.4e Chairs: Pascal Thubert Thomas Watteyne Etherpad for minutes: http://etherpad.tools.ietf.org:9000/p/6tisch?useMonospaceFont=true

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Agenda - Administrivia [2min] Minutes Last meetings - Status for draft-ietf-6tisch-architecture [5min] - Status for draft-ietf-6tisch-minimal [10min] - plugtest and hackathon news and dates [10min] - COMI and CoAP draft [15min] - Rechartering [10min] - AOB [3min]   4 4 4 4 4

Administrivia

Admin is trivia Approval Agenda Approval minutes ‘e’ removed from charter RFC 7554 (TSCH) is out!!! 6 6 6 6

Other Announcements New ETSI IP6 ISG The ETSI “IPv6 integration” Industry Specification Group (IP6 ISG) is a working group to focus on IPv6-based best practices, deployment guidelines and success showcases identifying thereby what and where consensus and harmonization could be reached.  We invite all interested parties from your organization or others to join in. Participation in the ISG IP6 is subject to signature of an ISG IP6 Agreement you can find at ETSI portal. Explanation about those agreements is also available from the same location. One standard of particular interest: “IPv6-based Industrial Internet leveraging 6TiSCH Technology” 7 7 7 7

Status for draft-ietf-6tisch-architecture

Proposal 08 published Intended Track: Informational All LC issues solved Shepherd write up taking place Thanks Shwetha !!! Authors are being polled for IPR All answered, OK there Next step IESG

draft-ietf-6tisch- minimal-07 Xavi Vilajosana (Ed.) Kris Pister

draft-ietf-6tisch-minimal-06 Status Status: Reworked sections 4 and 5 Referenced to examples Added examples at the end – Section 10 Needs to be finished: For example 2 and 3 add the byte stream in LSB draft-ietf-6tisch-minimal-06 11

5/14/2018

5/14/2018

5/14/2018

5/14/2018

5/14/2018

plugtest and hackathon news and dates

COMI and CoAP draft

Introducing CoMI Aligned with RestCONF (draft-ietf-netconf-restconf-04) Common data modeling language (YANG defined in RFC 6020) Protocol (CoAP instead of http) Security (DTLS instead of TLS) Payload encoded (CBOR instead of XML or JSON) Data node identifier (30 bit hash value instead of data node path) Hash values are encoded in base64 in URI, in binary in payload

Example RestCONF (214 bytes payload) CoMI (52 bytes payload) GET /restconf/data/ietf-6tisch-mac:TSCHSpecificPIBAttributes Host: example.com Accept: application/yang.data+json HTTP/1.1 200 OK Date: Mon, 23 Apr 2012 17:01:30 GMT Server: example-server Content-Type: application/yang.data+json { "ietf-6tisch:TSCHSpecificPIBAttributes" : { "macMinBE" : 3, "macMinBE" : 7, "macDisconnectTime" : 255, "macJoinPriority" : 1, "macASN" : 164926744166, "macNoHLBuffers" : true } REQ: GET example.com/mg/nDAal RES: 2.05 Content (Content-Format: application/cbor) a1 1a 270c06a5 a6 1a 18f1deec 03 1a 3a4367ae 07 1a 0fd897c1 18 ff 1a 0f817d75 01 1a 35920a57 1b 0000002666666666 1a 2386c778 f5

YANG hash clashes Hashes are computed using the murmur3 hash on the canonical representation of the data node path. For example: mmh3 ('/6top:TSCHSpecificPIBAttributes/6top:macMinBE', 42) = 418504428 or "Y8d7s" in base64 Hashes may be identical for different names, so- called clashes Hash clashes within a module can be detected and fixed at module design time Hash clashes between modules depend on the set of modules implemented by each CoMI server

YANG hash clashes Set of YANG hashes for Module A Set of YANG hashes for Module B Set of YANG hashes for Module C Hash clashes

Hash clashes handling as defined in draft-vanderstok-core-comi-06 CoMI servers with hash clashes need to implement a “rehash” list containing: The hash causing the clash The data node path A character appended to the path to resolve the clash CoMI clients need to retrieve the “rehash” list of each CoMI server prior to accessing them CoMI clients use the “rehash” list as a lookup table to associate the right data node with the right hash CoMI clients need to store the full data node names

Hash clashes handling as defined in draft-vanderstok-core-comi-06 CoMI client CoMI server #1 Path of each data node for lookup in “rehash” lists Server 1 “rehash” list Server n “rehash” list Data nodes 655099557, value 418504428, value (Rehash to 515761480) … “rehash” list 418504428, “/6top:TSCHSpecificPIBAttributes/6top:macMinBE”, “_” Step 2 Step 1 Step 1 Retrieve “rehash” list from server #1 to #n Step 2 For each access to data node, perform a lookup in “rehash” list to associate the right data node with the right hash CoMI server #n Data nodes 655099557, value 418504428, value … “rehash” list <empty>

First alternate solution (simplified “rehash” list) Assuming that hash clashes within each module are resolved at design time CoMI servers return a “hash clash” error only when a CoMI client tries to access data node(s) with hash clashes The CoMI client generates a simplified “rehash” list containing: The old hash The new hash The module identifier (local to client) The CoMI client uses the “rehash” list to resend the request with the proper hash

First alternate solution (simplified “rehash” list) CoMI client CoMI server #1 Step 1 Module name & data nodes hashes Server 1 “rehash” list Server n “rehash” list Data nodes 655099557, value 418504428, empty (Rehashed to 515761480) … “extend” list - 515761480 , value [ Step 3 ] [ Step 2 ] Step 1 Try to access a data node Step 2 If “hash clash” error receive, retrieve “rehash” from “clash_file” using module name, old hash” Step 3 Try again to access a data node with the rehash value CoMI server #n Data nodes 655099557, value 418504428, value … “rehash” list <empty>

Second alternate solution (No “rehash” list) Assuming that hash clashes within each module is resolved at design time CoMI servers return a “hash clash” error only when a CoMI client tries to access data node(s) with hash clashes On reception of a “hash clash” error, a CoMI client resends its request with the optional query parameter specifying the module name. Notes: This format can also be used all the time to avoid “hash clash” errors. “rehash” list are not required (to implement, to retrieve, to lookup) But requires communication overhead, and module name in server For example: GET example.com/Y8d7s?select= ietf-6tisch-mac Permanent query overhead

Second alternate solution (No “rehash” list) CoMI client CoMI server #1 Step 1 Module name & data nodes hashes Data nodes 655099557, ietf-6tisch-mac, value 418504428, ietf-6tisch-mac, value … [ Step 2 ] Step 1 Try to access a data node Step 2 If “hash clash” error receive, try again to access the data node with the module name added as optional query parameter. e.g. GET example.com/Y8d7s?select= ietf-6tisch-mac CoMI server #n Data nodes 655099557, ietf-6tisch-mac, value 418504428, ietf-6tisch-mac, value …

Third alternate solution (Managed IDs) Partially managed identifiers (Module ID) or fully managed identifiers (Module ID & Data node ID) Require IANA registration of each YANG module writer. Each writer need to assign module IDs and optionally data node IDs. Allows payload size reduction For example (24 bytes payload): REQ: GET example.com/mg/1&select(5) RES: 2.05 Content (Content-Format: application/cbor) a1 01 a6 02 03 07 04 18 ff 05 06 1b 0000002666666666 f5

Third alternate solution (Managed IDs) CoMI client CoMI server #1 Step 1 Module ID & data nodes ID Data nodes data node #1, module #5, value data node #2, module #5, value … Step 1 Access a data node e.g. GET example.com/mg/1&select(5) CoMI server #n Data nodes data node #1, module #5, value data node #2, module #5, value …

Other items to be discussed within CoMI Support of the YANG RPC Similar approach as the RestCONF RPC (protocol operations) Support of the YANG notification Similar approach as the RestCONF notification

Rechartering

Complete ? Archie 1 and TSCH Minimal CoAP and 6top interface

Additions Security Dynamic scheduling Requirements to DetNet Join Process More? In Archie 2? Dynamic scheduling OTF 6top Archie 2 Requirements to DetNet Track organization and operation

AOB ?

Thank you!