Minutes interim-2018-6tisch-01: Fri 16:00
IPv6 over the TSCH mode of IEEE 802.15.4e
||Minutes interim-2018-6tisch-01: Fri 16:00
## DRAFT ##
# Minutes, 26 January 2018 interim, 6TiSCH WG #
* Date: January 26th, 2018 7-8am Pacific
* Material link:
* Meeting number (access code): 204 172 595
* Meeting password: fcqY7cPj (32797275 from phones)
1. Xavi Vilajosana
1. Thomas Watteyne
1. Pascal Thubert
1. Diego Dujovne
1. Fabrice Theoleyre
1. Georgios Papadopoulos
1. Jonathan Munoz
1. Lotte Steenbrink
1. Mitsuru Kanda
1. Remous-Aris Koutsiamanis
1. Tengfei Chang
1. Yasuyuki Tanaka
1. Simon Duquennoy
1. Remy Liu
1. Rahul Jadhav
1. Carsten Boorman
Taking notes _(using Etherpad)_
1. Xavier Vilajosana
1. Pascal Thubert
* Xavi to review draft-papadopoulos-6tisch-pre-reqs
* admin [ 2min]
* draft-papadopoulos-6tisch-pre-reqs [20min]
* security update (Michael Richardson) [ 5min]
* 6LoWPAN Fragmentation (Thomas Watteyne) [25min]
* Any Other Business [ 3min]
* [07:05] Meeting starts
* [07:07] Admin update
* agenda and last meeting minutes are approved.
* IETF101 in london
* 90 min meeting
* 05/03/18 cutoff date
*- 12/03/18 final agenda
* [07:10] draft-papadopoulos-6tisch-pre-reqs
* Georgios Papadopoulos presents
* Presents about packet replication and elimination in 6tisch
* idea is to increase the reliability in a 6tisch network. Also influence
or improve jitter * suggest PRE (packet Replication and Elimination) can
help on jirtter and delivery ratio * Overhearing, replication and
elimination are the tools used to address the objectives * Need a cell with
more than one receiver for replication * replication-> each 6tisch node
transmit the packet to its preferred parent and a copy to another selected
parent. * Requirement is to define an alternate parent. This potentially
requires the extension of the DIO so this information is signaled and node
can know other information to select an alternative parent.
* TW: What information is sent through this DIO modification?
* G.P: the DIO contains information so one node cannot that there is a
common ancestor through their paths. * need cells to allow multiple
receivers * packet elimination through tagging.
* [07:35] Security Update
* Pascal and Thomas present on behalf of Michael and Malisa
* minimal security Status: resolved the issue on join traffic tagging. Not
* [07:40] Fragmentation update. Thomas Watteyne, chair of the Design Team,
* happened at 6lo
* Gabriel and Samita asked to create a fragmentation design team.
* the design team is chaired by Thomas W. Carsten, Pascal, Gabriel are part
* problem is that fragmentation requires per-hop reassembly.
* RFC4944 defines a fragment header. Packets are re-assembled and possibly
* there is a reassembly timer that expires if a hop do not receive all
* per hop-fragmentation and reassembly, this increases latency as the
packet progresses as the speed of the last fragment.
* Reliability is another problem as when fragments are lost keep the memory
occupied for some time. If there are other nodes transmitting and nodes
have memory limitation packets are dropped.
* When a fragment is lost all the packet is dropped and needs to restart
* -solution is fragment forwarding.
* Carsten's book, introduced the concept of virtual buffers, which mainly
imply that the address and header is kept in the node but the fragment is
actually forwarded immediately as it is received.
* new draft from carsten has been published at LWIG.Thomas is working on
integrating with some of his contributions.
* Outcomes of the Frag. DT|.
* 2 documents will be produced.
* informational document describing how fragmentation works. Discusses
* std track, builds on top of the first one. adds fragment recovery
* Xavi: Clarifying question: is ack per fragment
* Thomas: a bitmap indicates all the fragments and is transmitted by the the
destination. So this is end to end group ack once all fragments have been
received or a timeout has expired.