ROLL R. Koutsiamanis, Ed.
Internet-Draft G. Papadopoulos
Intended status: Standards Track N. Montavont
Expires: May 7, 2020 IMT Atlantique
P. Thubert
Cisco
November 4, 2019
Common Ancestor Objective Functions and Parent Set DAG Metric Container
Extension
draft-ietf-roll-nsa-extension-05
Abstract
Implementing Packet Replication and Elimination from / to the RPL
root requires the ability to forward copies of packets over different
paths via different RPL parents. Selecting the appropriate parents
to achieve ultra-low latency and jitter requires information about a
node's parents. This document details what information needs to be
transmitted and how it is encoded within a packet to enable this
functionality. This document also describes Objective Functions
which take advantage of this information to implement multi-path
routing.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 7, 2020.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Common Ancestor Objective Functions . . . . . . . . . . . . . 4
3.1. Common Ancestor Strict . . . . . . . . . . . . . . . . . 6
3.2. Common Ancestor Medium . . . . . . . . . . . . . . . . . 7
3.3. Common Ancestor Relaxed . . . . . . . . . . . . . . . . . 8
3.4. Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Node State and Attribute (NSA) object type extension . . . . 8
4.1. Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5. Controlling PRE . . . . . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Informative references . . . . . . . . . . . . . . . . . 11
8.2. Other Informative References . . . . . . . . . . . . . . 12
Appendix A. Implementation Status . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
Network-enabled applications in the industrial context must provide
stringent guarantees in terms of reliability and predictability. To
achieve this they typically leverage 1+1 redundancy, also known as
Packet Replication and Elimination (PRE)
[I-D.papadopoulos-6tisch-pre-reqs]. Allowing these kinds of
applications to function over wireless networks requires the
application of the principles of Deterministic Networking
[I-D.ietf-detnet-architecture]. This results in designs which aim at
optimizing packet delivery rate and bounding latency. Additionally,
given that the network nodes often do not have an unlimited power
supply, energy consumption needs to be minimized as well.
As an example, to meet this goal, IEEE Std. 802.15.4 [IEEE802154]
provides Time-Slotted Channel Hopping (TSCH), a mode of operation
which uses a common communication schedule based on timeslots to
allow deterministic medium access as well as channel hopping to work
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around radio interference. However, since TSCH uses retransmissions
in the event of a failed transmission, end-to-end delay and jitter
performance can deteriorate.
Furthermore, the 6TiSCH working group, focusing on IPv6 over IEEE
Std. 802.15.4-TSCH, has worked on the issues previously highlighted
and produced the "6TiSCH Architecture" [I-D.ietf-6tisch-architecture]
to address that case. Building on this architecture, "Exploiting
Packet Replication and Elimination in Complex Tracks in 6TiSCH LLNs"
[I-D.papadopoulos-6tisch-pre-reqs] leverages PRE to improve the
Packet Delivery Ratio (PDR), to provide a hard bound to the end-to-
end latency, and to limit jitter.
PRE is a general method of maximizing packet delivery rate and
potentially minimizing latency and jitter, not limited to 6TiSCH.
More specifically, PRE achieves controlled redundancy by laying
multiple forwarding paths through the network and using them in
parallel for different copies of a same packet. PRE can follow the
Destination-Oriented Directed Acyclic Graph (DODAG) formed by RPL
from a node to the root. Building a multi-path DODAG can be achieved
based on the RPL capability of having multiple parents for each node
in a network, a subset of which is used to forward packets. In order
for this subset to be defined, a RPL parent subset selection
mechanism, which is among the responsibilities of the RPL Objective
Function (OF), needs to have specific path information. This
document describes OFs which implement multi-path routing for PRE and
specifies the transmission of this specific path information.
For the OFs, this document specifies a group of OFs called Common
Ancestor (CA) OFs. A detailed description is made of how the path
information is used within the CA OF and how the subset of parents
for forwarding packets is selected. This specification defines a new
shared Objective Code Point (OCP) for these CA OFs.
For the path information, this specification focuses on the
extensions to the DAG Metric Container [RFC6551] required for
providing the PRE mechanism a part of the information it needs to
operate. This information is the RPL [RFC6550] parent address set of
a node and it must be sent to potential children of the node. The
RPL DIO Control Message is the canonical way of broadcasting this
kind of information and therefore its DAG Metric Container [RFC6551]
field is used to append a Node State and Attribute (NSA) object. The
node's parent address set is stored as an optional TLV within the NSA
object. This specification defines the type value and structure for
the parent address set TLV.
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2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
The draft uses the following Terminology:
Packet Replication and Elimination (PRE): A method which transmits
multiple copies of a packet using multi-path forwarding over a
multi-hop network and which consolidates multiple received packet
copies to control flooding. See "Exploiting Packet Replication
and Elimination in Complex Tracks in 6TiSCH LLNs"
[I-D.papadopoulos-6tisch-pre-reqs] for more details.
Alternative Parent (AP) Selection: The mechanism for choosing the
next hop node to forward a packet copy when replicating packets.
3. Common Ancestor Objective Functions
In the RPL protocol, each node maintains a list of potential parents.
For PRE, the Preferred Parent (PP) node is defined to be the same as
the RPL DODAG Preferred Parent node. Furthermore, to construct an
alternative path toward the root, in addition to the PP node, each
node in the network registers an AP node as well from its Parent Set
(PS).
There are multiple alternative methods of selecting the AP node.
This functionality is included in the operation of the RPL Objective
Function (OF). A group of OFs which allow the two paths to remain
correlated is detailed here. More specifically, when using these OFs
a node will select an AP node close to its PP node to allow the
operation of overhearing between parents. For more details about
overhearing and its use in this context see Section 4.3.
"Promiscuous Overhearing" in "Exploiting Packet Replication and
Elimination in Complex Tracks in 6TiSCH LLNs"
[I-D.papadopoulos-6tisch-pre-reqs]. If multiple potential APs match
this condition, the AP with the lowest rank will be registered.
The OFs described here are an extension of the The Minimum Rank with
Hysteresis Objective Function [RFC6719] (MRHOF) OF. In general,
these OFs extend MRHOF by specifying how an AP is selected.
Importantly, the calculation of the rank of the node though each
candidate neighbor and the selection of the PP is kept the same as in
MRHOF.
The ways in which the CA OFs modify MRHOF in a section-by-section
manner follows in detail:
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3. The Minimum Rank with Hysteresis Objective Function: Same as
MRHOF extended to AP selection. Minimum Rank path selection and
switching applies correspondingly to the AP with the extra CA
requirement of having some match between ancestors, depending on
the specific variant of CA OF used.
3.1. Computing the Path Cost: Same as MRHOF extended to AP
selection. If a candidate neighbor does not fulfill the CA
requirement then the path through that neighbor SHOULD be set to
MAX_PATH_COST. As a result, the node MUST NOT select the
candidate neighbor as its AP.
3.2. Parent Selection: Same as MRHOF extended to AP selection. To
allow hysteresis, AP selection maintains a variable,
cur_ap_min_path_cost, which is the path cost of the current AP.
3.2.1. When Parent Selection Runs: Same as MRHOF.
3.2.2. Parent Selection Algorithm: Same as MRHOF extended to AP
selection. If the smallest path cost for paths through the
candidate neighbors is smaller than cur_ap_min_path_cost by less
than PARENT_SWITCH_THRESHOLD, the node MAY continue to use the
current AP. Additionally, if there is no PP selected, there MUST
NOT be any AP selected as well. Finally, as with MRHOF, a node
MAY include up to PARENT_SET_SIZE-1 additional candidate neighbors
in its alternative parent set.
3.3. Computing Rank: Same as MRHOF.
3.4. Advertising the Path Cost: Same as MRHOF.
3.5. Working without Metric Containers: It is not possible to work
without metric containers, since CA AP selection requires
information from parents regarding their parent sets, which is
transmitted via the NSA object in the DIO Mectric Container.
4. Using MRHOF for Metric Maximization: Same as MRHOF.
5. MRHOF Variables and Parameters: Same as MRHOF extended to AP
selection. The CA OFs operate like MRHOF for AP selection by
maintaining separate:
AP: Corresponding to the MRHOF PP. Hysteresis is configured for
AP with the same PARENT_SWITCH_THRESHOLD parameter as in MRHOF.
The AP MUST NOT be the same as the PP.
Alternative parent set: Corresponding to the MRHOF parent set.
The size is defined by the same PARENT_SET_SIZE parameter as in
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MRHOF. The Alternative parent set MUST be a non-strict subset
of the parent set.
cur_ap_min_path_cost: Corresponding to the MRHOF
cur_min_path_cost variable. To support the operation of the
hysteresis function for AP selection.
6. Manageability: Same as MRHOF.
6.1. Device Configuration: Same as MRHOF.
6.2. Device Monitoring: Same as MRHOF.
Three OFs are defined which perform AP selection based on common
ancestors, named Common Ancestor Strict, Common Ancestor Medium, and
Common Ancestor Relaxed, depending on how restrictive the selection
process is. A more restrictive method will limit flooding but might
fail to select an appropriate AP, while a less restrictive one will
more often find an appropriate AP but might increase flooding. The
OFs are all represented with the same Objective Code Point (OCP):
TBD1.
All three OFs apply their corresponding common ancestor criterion to
filter the list of candidate neighbours in the alternative parent
set. The AP is then selected from the alternative parent set based
on Rank and using hysteresis as is done for the PP in MRHOF.
3.1. Common Ancestor Strict
In the CA Strict OF the node will check if its Preferred Grand Parent
(PGP), the PP of its PP, is the same as the PP of the potential AP.
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( R ) root
. PS(S) = {A, B, C, D}
. PP(S) = C
. PP(PP(S)) = Y
.
PS(A) = {W, X}
( W ) ( X ) ( Y ) ( Z ) PP(A) = X
^ ^ ^^ ^ ^ ^^^^ ^ ^ ^^
| \ // | \ // || \ / || PS(B) = {W, X, Y}
| // | // || / || PP(B) = Y
| // \ | // \ || / \ ||
| // \ | // \ || / \ || PS(C) = {X, Y, Z}
( A ) ( B ) ( C ) ( D ) PP(C) = Y
^ ^ ^^ ^
\ \ || / PS(D) = {Y, Z}
\ \ || / PP(D) = Z
\ \ || /
\----\\ || / || Preferred Parent
( S ) source | Potential Alternative Parent
Figure 1: Example Common Ancestor Strict Alternative Parent Selection
method
For example, in Figure 1, the source node S must know its grandparent
sets through nodes A, B, C, and D. The Parent Sets (PS) and the
Preferred Parents (PS) of nodes A, B, C, and D are shown on the side
of the figure. The CA Strict parent selection method will select an
AP for node S for which PP(PP(S)) = PP(AP). Given that PP(PP(S)) =
Y:
o Node A: PP(A) = X and therefore it is different than PP(PP(S))
o Node B: PS(B) = Y and therefore it is equal to PP(PP(S))
o Node D: PS(D) = Z and therefore it is different than PP(PP(S))
node S can decide to use node B as its AP node, since PP(PP(S)) = Y =
PP(B).
3.2. Common Ancestor Medium
In the CA Medium OF the node will check if its Preferred Grand Parent
(PGP), the PP of its PP, is contained in the PS of the potential AP.
Using the same example, in Figure 1, the CA Medium parent selection
method will select an AP for node S for which PP(PP(S)) is in PS(AP).
Given that PP(PP(S)) = Y:
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o Node A: PS(A) = {W, X} and therefore PP(PP(S)) is not in the set
o Node B: PS(B) = {W, X, Y} and therefore PP(PP(S)) is in the set
o Node D: PS(D) = {Y, Z} and therefore PP(PP(S)) is in the set
node S can decide to use node B or D as its AP node.
3.3. Common Ancestor Relaxed
In the CA Relaxed OF the node will check if the Parent Set (PS) of
its Preferred Parent (PP) has a node in common with the PS of the
potential AP.
Using the same example, in Figure 1, the CA Relaxed parent selection
method will select an AP for node S for which PS(PP(S)) has at least
one node in common with PS(AP). Given that PS(PP(S)) = {X, Y, Z}:
o Node A: PS(A) = {W, X} and the common nodes are {X}
o Node B: PS(B) = {W, X, Y} and the common nodes are {X, Y}
o Node D: PS(D) = {Y, Z} and the common nodes are {Y, Z}
node S can decide to use node A, B or D as its AP node.
3.4. Usage
The PS information can be used by any of the described AP selection
methods or other ones not described here, depending on requirements.
It is optional for all nodes to use the same AP selection method, and
because the CA OFs share the same OCP, they can do that withing the
same RPL Instance. Different nodes may use different AP selection
methods, since the selection method is local to each node. For
example, using different methods can be used to vary the transmission
reliability in each hop.
4. Node State and Attribute (NSA) object type extension
In order to select their AP node, nodes need to be aware of their
grandparent node sets. Within RPL [RFC6550], the nodes use the DODAG
Information Object (DIO) Control Message to broadcast information
about themselves to potential children. However, RPL [RFC6550], does
not define how to propagate parent set related information, which is
what this document addresses.
DIO messages can carry multiple options, out of which the DAG Metric
Container option [RFC6551] is the most suitable structurally and
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semantically for the purpose of carrying the parent set. The DAG
Metric Container option itself can carry different nested objects,
out of which the Node State and Attribute (NSA) [RFC6551] is
appropriate for transferring generic node state data. Within the
Node State and Attribute it is possible to store optional TLVs
representing various node characteristics. As per the Node State and
Attribute (NSA) [RFC6551] description, no TLV has been defined for
use. This document defines one TLV for the purpose of transmitting a
node's parent set.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RPLInstanceID |Version Number | Rank |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|G|0| MOP | Prf | DTSN | Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ DODAGID +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DAGMC Type (2)| DAGMC Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
// DAG Metric Container data //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Example DIO Message with a DAG Metric Container option
Figure 2 shows the structure of the DIO Control Message when a DAG
Metric Container option is included. The DAG Metric Container option
type (DAGMC Type in Figure 2) has the value 0x02 as per the IANA
registry for the RPL Control Message Options, and is defined in
[RFC6550]. The DAG Metric Container option length (DAGMC Length in
Figure 2) expresses the DAG Metric Container length in bytes. DAG
Metric Container data holds the actual data and is shown expanded in
Figure 3.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Routing-MC-Type|Res Flags|P|C|O|R| A | Prec | Length (bytes)| |MC
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Res | Flags |A|O| PS type | PS Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |NSA
| PS IPv6 address(es) ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: DAG Metric Container (MC) data with Node State and
Attribute (NSA) object body and a TLV
The structure of the DAG Metric Container data in the form of a Node
State and Attribute (NSA) object with a TLV in the NSA Optional TLVs
field is shown in Figure 3. The first 32 bits comprise the DAG
Metric Container header and all the following bits are part of the
Node State and Attribute object body, as defined in [RFC6551]. This
document defines a new TLV, which CAN be carried in the Node State
and Attribute (NSA) object Optional TLVs field. The TLV is named
Parent Set and is abbreviated as PS in Figure 3.
PS type: The type of the Parent Set TLV. The value is TBD2.
PS Length: The total length of the TLV value field (PS IPv6
address(es)) in bytes.
4.1. Usage
The PS SHOULD be used in the process of parent selection, and
especially in AP selection, since it can help the alternative path to
not significantly deviate from the preferred path. The Parent Set is
information local to the node that broadcasts it.
The PS is used only within NSA objects configured as constraints and
is used as per [RFC6551]. As a result, the PS does not affect the
calculation of the rank through candidate neighbors. It is only used
with the CA OFs to remove nodes which do not fulfill the CA OF
criteria from the candidate neighbor list.
5. Controlling PRE
PRE is very helpful when the aim is to increase reliability for a
certain path, however its use creates additional traffic as part of
the replication process. It is conceivable that not all paths have
stringent reliability requirements. Therefore, a way to control
whether PRE is applied to a path's packets SHOULD be implemented.
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For example, a traffic class label can be used to determine this
behavior per flow type as described in Deterministic Networking
Architecture [I-D.ietf-detnet-architecture].
6. Security Considerations
The structure of the DIO control message is extended, within the pre-
defined DIO options. Therefore, the security mechanisms defined in
RPL [RFC6550] apply to this proposed extension.
7. IANA Considerations
This proposal requests the allocation of a new value TBD1 from the
"Objective Code Point (OCP)" sub-registry of the "Routing Protocol
for Low Power and Lossy Networks (RPL)" registry. This proposal also
requests the allocation of a new value TBD2 for the "Parent Set" TLV
from the Routing Metric/Constraint TLVs sub-registry from IANA.
8. References
8.1. Informative references
[I-D.ietf-6tisch-architecture]
Thubert, P., "An Architecture for IPv6 over the TSCH mode
of IEEE 802.15.4", draft-ietf-6tisch-architecture-28 (work
in progress), October 2019.
[I-D.ietf-detnet-architecture]
Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", draft-ietf-
detnet-architecture-13 (work in progress), May 2019.
[I-D.papadopoulos-6tisch-pre-reqs]
Papadopoulos, G., Montavont, N., and P. Thubert,
"Exploiting Packet Replication and Elimination in Complex
Tracks in 6TiSCH LLNs", draft-papadopoulos-6tisch-pre-
reqs-02 (work in progress), July 2018.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
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[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012,
<https://www.rfc-editor.org/info/rfc6550>.
[RFC6551] Vasseur, JP., Ed., Kim, M., Ed., Pister, K., Dejean, N.,
and D. Barthel, "Routing Metrics Used for Path Calculation
in Low-Power and Lossy Networks", RFC 6551,
DOI 10.17487/RFC6551, March 2012,
<https://www.rfc-editor.org/info/rfc6551>.
[RFC6719] Gnawali, O. and P. Levis, "The Minimum Rank with
Hysteresis Objective Function", RFC 6719,
DOI 10.17487/RFC6719, September 2012,
<https://www.rfc-editor.org/info/rfc6719>.
8.2. Other Informative References
[IEEE802154]
IEEE standard for Information Technology, "IEEE Std
802.15.4 Standard for Low-Rate Wireless Personal Area
Networks (WPANs)", December 2015.
8.3. URIs
[1] https://github.com/ariskou/contiki/tree/draft-koutsiamanis-roll-
nsa-extension
[2] https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit
;h=e2f6ba229f45d8ccae2a6405e0ef41f1e61da138
Appendix A. Implementation Status
A research-stage implementation of the PRE mechanism using the
proposed extension as part of a 6TiSCH IOT use case was developed at
IMT Atlantique, France by Tomas Lagos Jenschke and Remous-Aris
Koutsiamanis. It was implemented on the open-source Contiki OS and
tested with the Cooja simulator. The DIO DAGMC NSA extension is
implemented with a configurable number of parents from the parent set
of a node to be reported.
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( R )
(11) (12) (13) (14) (15) (16)
(21) (22) (23) (24) (25) (26)
(31) (32) (33) (34) (35) (36)
(41) (42) (43) (44) (45) (46)
(51) (52) (53) (54) (55) (56)
( S )
Figure 4: Simulation Topology
The simulation setup is:
Topology: 32 nodes structured in regular grid as show in Figure 4.
Node S (source) is the only data packet sender, and send data to
node R (root). The parent set of each node (except R) is all the
nodes in the immediately higher row, the immediately above 6
nodes. For example, each node in {51, 52, 53, 54, 55, 56} is
connected to all of {41, 42, 43, 44, 45, 46}. Node 11, 12, 13,
14, 15, 16 have a single upwards link to R.
MAC: TSCH with 1 retransmission
Platform: Cooja
Schedule: Static, 2 timeslots per link from each node to each parent
in its parent set, 1 broadcast EB slot, 1 sender-based shared
timeslot (for DIO and DIS) per node (total of 32).
Simulation lifecycle: Allow link formation for 100 seconds before
starting to send data packets. Afterwards, S sends data packets
to R. The simulation terminates when 1000 packets have been sent
by S.
Radio Links: Every 60 s, a new Packet Delivery Rate is randomly
drawn for each link, with a uniform distribution spanning the 70%
to 100% interval.
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Traffic Pattern: CBR, S sends one non-fragmented UDP packet every 5
seconds to R.
PS extension size: 3 parents.
Routing Methods:
* RPL: The default RPL non-PRE implementation in Contiki OS.
* 2nd ETX: PRE with a parent selection method which picks as AP
the 2nd best parent in the parent set based on ETX.
* CA Strict: As described in Section 3.1.
* CA Medium: As described in Section 3.2.
Simulation results:
+----------+---------------+------------------+---------------------+
| Routing | Average | Average | Average |
| Method | Packet | Traversed | Duplications/packet |
| | Delivery Rate | Nodes/packet (#) | (#) |
| | (%) | | |
+----------+---------------+------------------+---------------------+
| RPL | 82.70 | 5.56 | 7.02 |
| 2nd ETX | 99.38 | 14.43 | 31.29 |
| CA | 97.32 | 9.86 | 18.23 |
| Strict | | | |
| CA | 99.66 | 13.75 | 28.86 |
| Medium | | | |
+----------+---------------+------------------+---------------------+
Links:
o Contiki OS DIO DAGMC NSA extension (draft-koutsiamanis-roll-nsa-
extension branch) [1]
o Wireshark dissectors (for the optional PS TLV) - currently merged
/ in master [2]
Authors' Addresses
Koutsiamanis, et al. Expires May 7, 2020 [Page 14]
Internet-Draft CA OF and PS DAG MC Extension November 2019
Remous-Aris Koutsiamanis (editor)
IMT Atlantique
Office B00 - 126A
2 Rue de la Chataigneraie
Cesson-Sevigne - Rennes 35510
FRANCE
Phone: +33 299 12 70 49
Email: aris@ariskou.com
Georgios Papadopoulos
IMT Atlantique
Office B00 - 114A
2 Rue de la Chataigneraie
Cesson-Sevigne - Rennes 35510
FRANCE
Phone: +33 299 12 70 04
Email: georgios.papadopoulos@imt-atlantique.fr
Nicolas Montavont
IMT Atlantique
Office B00 - 106A
2 Rue de la Chataigneraie
Cesson-Sevigne - Rennes 35510
FRANCE
Phone: +33 299 12 70 23
Email: nicolas.montavont@imt-atlantique.fr
Pascal Thubert
Cisco Systems, Inc
Building D
45 Allee des Ormes - BP1200
MOUGINS - Sophia Antipolis 06254
FRANCE
Phone: +33 497 23 26 34
Email: pthubert@cisco.com
Koutsiamanis, et al. Expires May 7, 2020 [Page 15]