mobility, traffic engineering and redundancy using rpl

Traffic engineering, redundancy and mobility with RPLand several border routers

Maxime Denis

Departement d’InformatiqueUniversite de Mons

June 21th 2013

Director : Pr. Bruno Quoitin External experts : M. Sebastien DawansReviewers : Pr. Sebastien Bette M. Laurent Deru

M. Mathieu Michel

Summary

Outline

1 Introduction

2 Background

3 Multi-BR problematic

4 State of the art

5 Validation

6 Conclusion

Maxime Denis (UMONS) Traffic engineering, redundancy and mobility with RPL June 21th 2013 2 / 29

Introduction

Introduction

Figure 1 : WSN layout on the bridge[1].

Wireless Sensors Network (WSN)

Set of sensors, i.e., devices with limited capabilities, often with energyconstraints and wireless interface.

Internet of Things (IoT)

Allows Internet connectivity for any devices : Smart Cities, Smart Building,Smart Grids, Smart . . .IoT = interconnection of WSNs.


Introduction

Interfacing WSNs with classical networks

With Border Routers (BRs)

A sensor with two stacks, bridging the WLAN and the WSN ;

Most of the time a more capable sensor without energyconstraints ;

In this master thesis : interconnection between IEEE 802.15.4 andEthernet.


Introduction

Master thesis subject

Study the interconnection through multiple BRs with a focus on :

1 Redundancy ;

2 Mobility ;

3 Traffic engineering.

using RPL and Contiki.Maxime Denis (UMONS) Traffic engineering, redundancy and mobility with RPL June 21th 2013 5 / 29

Background

Outline

1 Introduction

2 BackgroundIPv6StacksRPLContiki


4 State of the art

5 Validation

6 Conclusion


Background IPv6

IPv6

IPv6 [2, 3, 4]

large address space (2128 adresses) ;

minimal MTU (1280 Bytes) ;

autoconfiguration process (NDP) ;

...

Neighbor Discovery Protocol [5]

contains ARP (IPv4) ;

Autoconfiguration using the Duplicate Address Detection (DAD)mechanism ;

Reachability detection using the Neighbor Unreachability Detection(NUD).


Background Stacks

Stacks

IPv6

ICMPNDP UDP TCP

802.3 MAC layer802.3 PHY layer

Figure 2 : Classical stack.

IPv6

ICMPRPL UDP TCP

802.15.4 MAC layer

802.15.4 PHY layer

6LoWPAN layer

Figure 3 : WSN stack.


Background RPL

Routing Protocol for Lossy networks (RPL)

Lightweight distance vector protocol [6] used in WSNs.

Description

Collect oriented : designed to collect data from sensors to sink.

Topology covered by a tree with a single root.

Datapath validation : no periodical messages.

Two concepts : instances and DODAGs (Destination OrientedDirected Acyclic Graphs).

Traffic

RPL allows three kinds of traffic : Peer-to-Peer, Peer-to-Multi-Peer andMulti-Peer-to-Peer.


Background RPL

DODAGs

DODAG : tree covering and partitioning the WSN.

Root : node managing the DODAG ;

Upward routes : created by DIOs, to reach the root ;

A node owns a parent which leads to the root ;

Downward routes : created by DAOs, to reach the sensor ;

Node’s rank means the distance between the node and the root ;

Metrics are used to qualify links and choose parents ;


Background RPL

Instances

Set of DODAGs, optimized for a QoS or designed for a constraint.

Rules

A node can join only a single DODAG per instance ;

A node can join all the instances available ;

A node may not join an instance if the QoS is not appropriate.


Background Contiki

Contiki : a lightweight operating system for WSNs

Description

Real time operating system [7], for embedded platforms.

What Contiki brings

uIP stack : small IPv6 (or IPv4) compliant stack, few RAM, singleinterface support ;


Multi-BR problematic

Outline

1 Introduction

2 Background

3 Multi-BR problematicMobilityRedundancyTraffic engineeringExtracted RPL root

4 State of the art

5 Validation

6 Conclusion


Multi-BR problematic Mobility

Mobility

Mobility case

Parent failure : switching to another parent in the DODAG.

Mobility : new neighborhood : DODAG ? Instance ?

In multi-BR case...



MobilityMobility case



In multi-BR case...



Mobility

Mobility case



In multi-BR case...


Multi-BR problematic Redundancy

Redundancy

Redundancy consequences

Border router failures : recovery increased ;

RPL overhead on sensors (several DODAGs).


Multi-BR problematic Traffic engineering

Traffic engineering

Force paths on the WSN to balance the traffic among several paths.

Solutions

Multi-instance to balance traffic over sensors ;

Multi-instance over several channels to balance traffic over channels.


Multi-BR problematic Extracted RPL root

Implementation : extracted RPL root over Ethernet

1 RPL root over Ethernet ;

2 Border routers running in a single DODAG per instance ;

3 Mobility and redundancy increased, complexity decreased.


State of the art

Outline

1 Introduction

2 Background


4 State of the art6LBR

5 Validation

6 Conclusion


State of the art

Existing 6LoWPAN border router solutions

Computer dependant

Contiki’s border router integrated solution ;

Jackdaw USB stick [8] ;

Computer independant

Grinch project[9] ;

6LoWPAN-ND on Hogaza platform[10] ;

CETIC’s 6LBR[11, 12].


State of the art 6LBR

6LBR

Features

6LoWPAN border router using RPL ;

Support of two interfaces in Contiki (filtering rules and translation).

Platforms

Linux native (PC, Raspberry Pi, BeagleBone), Redwire Econotag withEthernet controller.


Validation

Outline

1 Introduction

2 Background


4 State of the art

5 ValidationConfigurationExperimentationsResults

6 Conclusion


Validation Configuration

Scenarios

Platforms

Zolertia Z1 (N1, N2, BR2) ;

Crossbow TelosB (BR1) ;

Four scenarios captured in five experimentations. Traffic capture doneusing sniffer[13]. Traces in pcap format and sequence diagrams,performance indication (values measured in traces).


Validation Experimentations

Scenario 1 (S1) : Multi-instance advertisement

Multi-instance advertisement and the route creation with packetexchange between the WSN and the Ethernet using the extracted RPLroot. A single BR and a single sensor are used in this scenario.





BR 802.15.4EthernetRPL Root

DIO(instance=2)DIO(instance=2)

DAO(instance=2, target=BR)

DAO(instance=1, target=BR)

DIO(instance=1)DIO(instance=1)

DIO(instance=2)

DIO(instance=1)

DAD(global)

DAD(link-local)

Visual Paradigm for UML Standard Edition(University of Mons)





1

2

3

(3) Time

Sensor

802.15.4RPL Root Ethernet BR

UDP(Ack)UDP(Ack)

UDP UDP

DIO(instance=1)

DIO(instance=1)

DAO(instance=1, target=Sensor)

DIS

Sensor turned on

DIO(instance=2)

DIO(instance=1)

DAO(instance=1, target=Sensor)

DIO(instance=2)

DIO(instance=1)




Scenario 4 (S4) : Mobility

A single instance with two BRs and a single sensor. Simulation of mobilitybetween two BRs.





Ethernet 802.14.5

Sensor

BR1RPL root

DIO

DIO

DIO

DIO

DIODIO

DAD(global)

DAD(link-local)

UDP

DAO(target=Sensor)

UDP

UDP

DAO(target=Sensor)

UDP

DAO(target=BR1)

DAO(target=BR1)

UDP(Ack)UDP(Ack)






2

1

(1) Time

802.14.5Ethernet

BR2

SensorBR1RPL root

UDP UDP

UDP UDP

DAO(target=Sensor)

DIODAO(target=BR2)

DIS

UDP

DIO

DIS

UDP UDP

UDP(Ack)

DAO(target=Sensor)

UDP(Ack)

UDP

UDP

UDP

UDP(Ack)UDP(Ack)



Validation Results

Results - S1 and S4

Summary of the main values gathered during scenarios

Route creation (S1) : about 7s ;

Retransmissions in mobility (S4) : about 30 ;

Route recreation after switch (S4) : about 18s.


Conclusion

Outline

1 Introduction

2 Background


4 State of the art

5 Validation

6 ConclusionContributionsFuture work


Conclusion Contributions

Contributions

1 Complete description of the background notions used : RPL,IPv6, NDP, 6LoWPAN and IEEE 802.15.4. ;

2 State of the art of the existing BRs solutions ;

3 The multi-BR problematic developed using redundancy, mobilityand traffic engineering ;

4 Design and implementation of the extracted RPL root and theborder routers ;

5 Four scenarios with traces and sequence diagrams ;

6 Multi-instance validation.


Conclusion Future work

Future work

1 Implementation of several instances using several channels ;

2 Dynamic load balancing implementation ;

3 Dynamic instance determination for Ethernet traffic ;

4 Validation using other applications (e.g., Pings, HTTP) ;

5 Bigger testbed and simulation validation ;

6 More realistic topologies (border routers and RPL root connectedthrough a backbone network) ;

7 ...



Thank you for your attention



[1] Sukun Kim, Shamim Pakzad, David Culler, James Demmel, GregoryFenves, Steven Glaser, and Martin Turon, “Health Monitoring of CivilInfrastructures Using Wireless Sensor Networks.” http:

//www.cs.berkeley.edu/~binetude/work/ipsn07_ggb.pdf (lastaccess : 12/05/13).

[2] J.-P. Vasseur and A. Dunkels, Interconnecting smart objects with IP.Morgan Kauffman, 2012.

[3] B. Quoitin, “IPv6.” Computer Networks course (UMONS).

[4] Internet Engineering Task Force, “RFC 2460 : Internet Protocol,Version 6 (IPv6) Specification.”http://tools.ietf.org/html/rfc2460 (last access : 16/03/13).

[5] Internet Engineering Task Force, “RFC 4861 : Neighbor Discovery forIP version 6 (IPv6).”https://datatracker.ietf.org/doc/rfc4861/ (last access :2/10/12).


http://www.cs.berkeley.edu/~binetude/work/ipsn07_ggb.pdf

http://www.cs.berkeley.edu/~binetude/work/ipsn07_ggb.pdf

http://tools.ietf.org/html/rfc2460

https://datatracker.ietf.org/doc/rfc4861/


[6] Internet Engineering Task Force, “RFC 6550 : RPL : IPv6 RoutingProtocol for Low-Power and Lossy Networks.”https://datatracker.ietf.org/doc/rfc6550/ (last access :2/10/12).

[7] “Contiki 2.6 Doxygen.”http://contiki.sourceforge.net/docs/2.6/ (last access :17/09/12).

[8] “Jackdaw USB stick.”http://dak664.github.com/contiki-doxygen/a01677.html

(last access : 2/10/12).

[9] “Grinch - simple 6lowpan RPL border router.”http://sixpinetrees.blogspot.be/2011/06/

grinch-simple-6lowpan-rpl-border-router.html (last access :2/10/12).


https://datatracker.ietf.org/doc/rfc6550/

http://contiki.sourceforge.net/docs/2.6/

http://dak664.github.com/contiki-doxygen/a01677.html

http://sixpinetrees.blogspot.be/2011/06/grinch-simple-6lowpan-rpl-border-router.html

http://sixpinetrees.blogspot.be/2011/06/grinch-simple-6lowpan-rpl-border-router.html


[10] L. M. Ara, “Neighbor Discovery Proxy-Gateway for 6LoWPAN-basedWireless Sensor Networks.” KTM Information and CommunicationTechnology.

[11] Maxime Denis, “6LoWPAN Border Router prototype on a RedwireEconotag,” February 2013.

[12] CETIC, “A deployment-ready 6LoWPAN Border Router solutionbased on Contiki.” https://github.com/cetic/6lbr (last access :23/02/13).

[13] David Hauweele, “Wsn tools.”https://github.com/gawen947/wsn-tools (last access :22/05/13).


https://github.com/cetic/6lbr

https://github.com/gawen947/wsn-tools

mobility, traffic engineering and redundancy using rpl

Technology

trac rpl

background rpl dodags

root metrics

root downward routes

single root

kinds of trac

dodag upward routes

background ipv6 ipv6