IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch) Internet Drafts


      
 An Architecture for IPv6 over the TSCH mode of IEEE 802.15.4
 
 draft-ietf-6tisch-architecture-30.txt
 Date: 26/11/2020
 Authors: Pascal Thubert
 Working Group: IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch)
 Formats: txt html xml
This document describes a network architecture that provides low- latency, low-jitter and high-reliability packet delivery. It combines a high-speed powered backbone and subnetworks using IEEE 802.15.4 time-slotted channel hopping (TSCH) to meet the requirements of LowPower wireless deterministic applications.
 Constrained Join Protocol (CoJP) for 6TiSCH
 
 draft-ietf-6tisch-minimal-security-15.txt
 Date: 10/12/2019
 Authors: Malisa Vucinic, Jonathan Simon, Kris Pister, Michael Richardson
 Working Group: IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch)
 Formats: txt xml
This document describes the minimal framework required for a new device, called "pledge", to securely join a 6TiSCH (IPv6 over the TSCH mode of IEEE 802.15.4e) network. The framework requires that the pledge and the JRC (join registrar/coordinator, a central entity), share a symmetric key. How this key is provisioned is out of scope of this document. Through a single CoAP (Constrained Application Protocol) request-response exchange secured by OSCORE (Object Security for Constrained RESTful Environments), the pledge requests admission into the network and the JRC configures it with link-layer keying material and other parameters. The JRC may at any time update the parameters through another request-response exchange secured by OSCORE. This specification defines the Constrained Join Protocol and its CBOR (Concise Binary Object Representation) data structures, and describes how to configure the rest of the 6TiSCH communication stack for this join process to occur in a secure manner. Additional security mechanisms may be added on top of this minimal framework.
 IEEE 802.15.4 Information Element encapsulation of 6TiSCH Join and Enrollment Information
 
 draft-ietf-6tisch-enrollment-enhanced-beacon-14.txt
 Date: 21/02/2020
 Authors: Diego Dujovne, Michael Richardson
 Working Group: IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch)
 Formats: html txt xml
In TSCH mode of IEEE STD 802.15.4, opportunities for broadcasts are limited to specific times and specific channels. Routers in a Time- Slotted Channel Hopping (TSCH) network transmit Enhanced Beacon (EB) frames to announce the presence of the network. This document provides a mechanism by which additional information critical for new nodes (pledges) and long sleeping nodes may be carried within the Enhanced Beacon in order to conserve use of broadcast opportunities.
 6TiSCH Minimal Scheduling Function (MSF)
 
 draft-ietf-6tisch-msf-18.txt
 Date: 12/09/2020
 Authors: Tengfei Chang, Malisa Vucinic, Xavier Vilajosana, Simon Duquennoy, Diego Dujovne
 Working Group: IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch)
 Formats: xml html txt
This specification defines the 6TiSCH Minimal Scheduling Function (MSF). This Scheduling Function describes both the behavior of a node when joining the network, and how the communication schedule is managed in a distributed fashion. MSF is built upon the 6TiSCH Operation Sublayer Protocol (6P) and the Minimal Security Framework for 6TiSCH.


IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch)

WG Name IPv6 over the TSCH mode of IEEE 802.15.4e
Acronym 6tisch
Area Internet Area (int)
State Active
Charter charter-ietf-6tisch-02 Approved
Dependencies Document dependency graph (SVG)
Additional Resources
- Issue tracker
- Repos
- Wiki
Personnel Chairs Pascal Thubert 
Thomas Watteyne 
Area Director Erik Kline 
Mailing list Address 6tisch@ietf.org
To subscribe https://www.ietf.org/mailman/listinfo/6tisch
Archive https://mailarchive.ietf.org/arch/browse/6tisch/
Jabber chat Room address xmpp:6tisch@jabber.ietf.org?join
Logs https://jabber.ietf.org/logs/6tisch/

Charter for Working Group

6TiSCH: "IPv6 over the TSCH mode of IEEE 802.15.4e".

Background/Introduction:
------------------------

Low-power and Lossy Networks (LLNs) interconnect a possibly large number
of resource-constrained nodes to form a wireless mesh network. The
6LoWPAN, ROLL and CoRE IETF Working Groups have defined protocols at
various layers of the protocol stack, including an IPv6 adaptation
layer, a routing protocol and a web transfer protocol. This protocol
stack has been used with IEEE802.15.4 low-power radios.

The Timeslotted Channel Hopping (TSCH) mode was introduced in 2012 as an
amendment to the Medium Access Control (MAC) portion of the IEEE802.15.4
standard. TSCH is the emerging standard for industrial automation and
process control LLNs, with a direct inheritance from WirelessHART and
ISA100.11a. Defining IPv6 over TSCH, 6TiSCH is a key to enable the
further adoption of IPv6 in industrial standards and the convergence of
Operational Technology (OT) with Information Technology (IT).

The nodes in a IEEE802.15.4 TSCH network communicate by following a
Time Division Multiple Access (TDMA) schedule. A timeslot in this
schedule provides a unit of bandwidth that is allocated for
communication between neighbor nodes. The allocation can be programmed
such that the predictable transmission pattern matches the traffic. This
avoids idle listening, and extends battery lifetime for constrained
nodes. Channel-hopping improves reliability in the presence of narrow-
band interference and multi-path fading.

These techniques enable a new range of use cases for LLNs, including:
- Control loops in a wireless process control network, in which high
reliability and a fully deterministic behavior are required.
- Service Provider networks transporting data from different independent
clients, and for which an operator needs flow isolation and traffic
shaping.
- Networks comprising energy harvesting nodes, which require an
extremely low and predictable average power consumption.

IEEE802.15.4 only defines the link-layer mechanisms. It does not define
how the network communication schedule is built and matched to the
traffic requirements of the network.

Description of Working Group:
-----------------------------

The Working Group will focus on enabling IPv6 over the TSCH mode of the
IEEE802.15.4 standard. The extent of the problem space for the WG is
one or more LLNs, possibly federated through a common backbone link
via one or more LLN Border Routers (LBRs). The WG will rely on, and if
necessary extend, existing mechanisms for authenticating LBRs.

Initially, the WG has limited its scope to distributed routing over a
static schedule using the Routing Protocol for LLNs (RPL) on the
resulting network. This new charter allows for the dynamic allocation of
cells and their exchange between adjacent peers to accommodate the
available bandwidth to the variations of throughput in IP traffic.

The WG will continue working on securing the join process and making
that fit within the constraints of high latency, low throughput and
small frame sizes that characterize IEEE802.15.4 TSCH.

Additionally, IEEE802.15.4 TSCH being a deterministic MAC, it is
envisioned that 6TiSCH will benefit from the work of DetNet WG to
establish the so-called deterministic tracks. The group will define the
objects and methods that need to be configured, and provide the
associated requirements to DetNet.

The WG will interface with other appropriate groups in the IETF
Internet, Operations and Management, Routing and Security areas.

Work Items:
-----------

The group will:

- Produce a specification of the 6top sublayer that describes the
protocol for neighbor nodes to negotiate adding/removing cells. This
work will leverage cross participation from IEEE members including the
IEEE 6TiSCH Interest Group (IG 6T) to define protocol elements and
associated frame formats.

- Produce a specification for a default 6top Scheduling Function
including the policy to enable distributed dynamic scheduling of
timeslots for IP traffic. This may include the capability for nodes to
appropriate chunks of the matrix without starving, or interfering with
other 6TiSCH nodes. This particular work will focus on IP traffic since
the work on tracks is not yet advanced enough to specify their
requirements.

- Produce requirements to the DetNet WG, detailing 6TiSCH chunks and
tracks, and the data models to manipulate them from an external
controller such as a PCE.

- Produce a specification for a secure 6TiSCH network bootstrap, adapted
to the constraints of 6TiSCH nodes and leveraging existing art when
possible.

- Keep updating the "6TiSCH architecture" that describes the design of
6TiSCH networks. This document highlights the different architectural
blocks, signaling and data flows, including the operation of the network
in the presence of multiple LBRs. The existing document will be
augmented to cover dynamic scheduling and application of the DetNet work
but will not be delivered within this round of chartering.

- Producing YANG Data Models to manage 6tisch is foreseen, but left to a
later phase.

Non-milestone work items:
-------------------------

The Working Group regularly organizes interoperability events with
support from ETSI (i.e., ETSI 6TiSCH Plugtests) to get feedback from
implementers early on in the standardization process, and produce better
standards.

Milestones

Date Milestone
1 Dec 2018 Evaluate WG progress, propose new charter to the IESG
1 Oct 2018 Initial submission of draft-ietf-6tisch-dtsecurity-zerotouch-join to the IESG

Done milestones

Date Milestone
Done 6TiSCH architecture and terminology in RFC publication queue
Done Initial submission of 6TiSCH architecture to the IESG
Done Initial submission of draft-ietf-6tisch-minimal-security to the IESG
Done Initial submission of draft-ietf-6tisch-6top-protocol to the IESG
Done ETSI 6TiSCH #3 plugtests
Done WG call to adopt draft-ietf-6tisch-6top-sublayer
Done WG call to adopt draft-ietf-6tisch-6top-sf0
Done Second submission of draft-ietf-6tisch-minimal to the IESG

2 new milestones currently in Area Director review.