A Hybrid QoS Routing Strategy for Suburban Ad-Hoc Networks Muhammad Mahmudul Islam Ronald Pose Carlo Kopp School of Computer Science & Software Engineering.

A Hybrid QoS Routing Strategy for

Suburban Ad-Hoc Networks

Muhammad Mahmudul IslamRonald Pose Carlo Kopp

School of Computer Science & Software EngineeringMonash University

Outline

IntroductionOverview of SAHN

Routing in SAHN (SAHNR)Simulation Results

Future WorkAcknowledgements

Introduction (1/4)

How to Connect to University's Network from Home

Commercial Wired Services Direct Dial-up Services Internet Services

Dial-up Broadband (cable modems, xDSL etc)

Ad-Hoc Wireless Networks Single Hop Solutions

802.11b Multi Hop Solutions

Nokia Roof-Top SAHN MIT Roofnet

Introduction (2/4)Limitations of commercial services

Impose service charges Require costly wiring infrastructure Not widely available Provide mostly asymmetric bandwidth utilization Inadequate for file transfer, X protocol, interactive

graphical programs etcISP

LocalTelephone

Office

LocalTelephone

Office

Local TelephoneOffice

Introduction (3/4)Limitations of single hop ad-hoc networks

Must have direct connectivity to all nodes Longer distances

may be covered

with higher

transmission energy Interference may increase as connectivity

increases Overall network throughput may decrease

Introduction (4/4)

Limitations of Nokia RoofTop

A central admninistrator has control over the whole network through RMS to Assign addresses to each node Change subscribers’ setting

Unable to detect rogue/non-cooperating nodes Authetication scheme using 16 bit key

SAHN (1/2) Provides services not offered by commercial service

providers Bypass expensive infrastructure for broadband Provide symmetric bandwidth WLAN in inadequate wiring infrastructure Bypass ongoing service charges for Telco independent

traffic Features multi-hop QoS routing

Security throughout all layers Utilizing link states (e.g. available bandwidth, link stability,

latency, jitter and security) to select suitable routes Avoid selfish routing strategy to avoid congestion Proper resource access control and management

SAHN (2/2) Ideal for cooperative nodes. E.g. spread over a suburban area,

connecting houses and business Topology is quasi static Uses wireless technology Symmetric broadband, multi Mbps bandwidth No charges for SAHN traffic SAHN services

run alongside

TCP/IP Conceived by

Ronald Pose

&

Carlo Kopp in 1997

Application

Presentation

Session

Transport

Network

Data Link

Physical

TCP/UDP

IP

Application

Presentation

Session

Transport

Network

Data Link

Physical

TCP/UDP

IP

SAHN Routing

e.g. IEEE 802.11 variants

e .g. IEEE 802.11 variants

AUDIO

VEDIO

OTHER

Appears to host like a cable modem Functionally more like a

RF LAN repeater Embedded

microprocessor &

protocol engine

that implements all

SAHN protocols, manages

and configures the system Each SAHN node has at least 2 wireless links Capable of achieveing link rate throughput

A Standard SAHN Node

References R. Pose and C. Kopp. Bypassing the Home Computing

Bottleneck: The Suburban Area Network. 3rd Australasian

Comp. Architecture Conf. (ACAC). February, 1998. pp.87-

100. A. Bickerstaffe, E. Makalic and S. Garic. CS honours theses.

Monash University. www.csse.monash.edu.au/~rdp/SAN/.

2001 Paul Conilione. QoS for Suburban Ad Hoc Networks.

Honours Interim Presentation, CSSE, Monash University, 5th

June 2003 MIT Roofnet. http://www.pdos.lcs.mit.edu/roofnet/

Design Challenges for SAHN Routing (1/2)

Wireless medium inherently vulnerable toEavesdroppingDoS attacksNode masquerading

Requires security policies implemented at all levels

Wireless technologies (e.g. 802.11) do not featureResource access controlResource management

Requires higher level protocols to efficiently handle limited resources

Design Challenges for SAHN Routing (2/2)

Ad-Hoc wireless networks should handle node/link failures find routes on demand route packets with required QoS detect non-cooperating nodes

Requires an efficient on-demand routing solution

Possible Routing Solutions for SAHN (1/3)

TableDriven

OnDemand

Hybrid

GSP

DSDV

HSR

WRP

FSR

MSR

DSR

TORA

AODV

AOMDV

Ad-Hoc Routing Protocols

LANMAR

QoSRouting


Dynamic source routing (DSR) On demandUses source routingCan find multiple routesNetwork overhead increases for carrying

source routesNo security at network layerDoes not consider QoS for route selectionDoes not feature load balancingCannot detect non-cooperating nodes

Ad Hoc on demand distance vector (AODV) routingOn demandCannot find multiple routes to a destinationNo security at network layerDoes not consider QoS for route selectionNo support for load balancingCannot detect non-cooperating nodes


Existing ad-hoc routing solutions do not feautrure one or more of the following attributes

Multiple routes to a destinationResource Access ControlQoSLoad balancingSecurity at network layerOptimization for quasi-static networksHandling non-cooperating nodes

Why Customized Routing for SAHN (1/2)

Mobile IP (IPv6)Uses proactive routing technique ideal for

centralized networksWhole network is flooded with link state

informationAssumes direct link (single hop) between

home/foreign agent and each hostCannot not handle non-cooperating nodes

Why Customized Routing for SAHN (2/2)

Uses source routing for route discovery Maintains routes dynamically

similar to DSR

e.g. gratuitous Route replies, salvaging data/error packets etc

Properties of SAHN Routing Protocol (1/2)

Decreases network overhead Excludes source route in every data packet

Avoids selfish/uncoordinated routing strategy Makes use of available paths having QoS Chooses least congested paths Balances load among available paths

Features network level security with least network overhead Node authentication Encryption of packet information Handling non-cooperative nodes

Properties of SAHN Routing Protocol (2/2)

Focus of this PaperModified DSR to

decrease network overhead by excluding source route in every data packet

avoid selfish/uncoordinated routing strategy by choosing least congested paths

feature network level security by encryption of packet information

QoS parameters for SAHNRAvailable bandwidth (bypass congested paths)Network level encryption for each session

Phases of SAHNR

Route Discovery

On demand Data Transmission

On demand Route Maintenance

Periodically and on demand

• Node Authentication• Exchange of keysare done in these phases

Network Level Security at a Glance RREQ packets contain

1. Public key

ACKRREQ packets contain 1. Public key2. Shared key 3. Identification signature

1 & 2 are encrypted with down stream nodes’ public key

Initial DATA packet for a session contains1. Shared key2. Identification signature

1& 2 are encrypted with upstream nodes’ public key

from upstream nodes

from downstream nodes

from downstream nodes

Neighbour Discovery & Security (1/8)

Requires RREQ, ACKRREQ, RREP & ACKRREP packets

Authentication and negotiation of shared key for encrytion/decryption of data packet is performed

SAHNId

TypeLocal

SourceAddress

TotalSize

CRCLevel1

GlobalSourceAddress

GlobalDestination

Address

RIL. Each node's address &QoS values

Level 1

Level 2 SEQ HCHTL

Level 2 Data

Public key of thetransmitting node

(for RREQ)

RREQ/RREP Packet Format

S wants to find route to X Generates [public key (PbS), private key(PrS)]

NS

G

H

FE

X

D

C

B


S broadcasts RREQS packets to its neighbours with PbS

NS

G

H

FE

X

D

C

BRREQS{S,PbS,QoSS}

RREQS


B generates [ PbB, PrB] & a shared key (ShB)

Encrypts ShB & B’s identification signature with PbS

Unicasts ACKRREQ with e(ShB+B,PbS) & PbB to S

Rebroadcasts RREQ packets to its neighbours with PbB

NS

G

H

FE

X

D

C

BACKRREQB{e(ShB+B,PbS),PbB}

RREQB{(S,QoSS)(B,PBB,QoSB)}

RREQB


S gets ShB & B’s identification signature by decryption

d(e(ShB+B,PbS), PrS)

Registers B as a valid node if its signature matches node identification table

NS

G

H

FE

X

D

C

BACKRREQC{e(ShC+C,PbB), PbC}

RREQC{(S,QoSS)(B,QoSB)(C,PBC,QoSC)}

RREQC RREQC


H receives RREQE from E

H has route to X

NS

GF

X

D

ACKRREQERREQE{(S,QoSS)(B,QoSB)(C,QoSC)(E,PbE,QoSE)}

RREQE

Route Table(RTH)::(X,QoSX):

B

C

E

H


NS

GF

X

DB

C

E

H

RouteTable(RTS):::

RREQE{(S,QoSS)(B,QoSB)(C,QoSC)(E,QoSE)}

Route Table(RTH)(S,QoSS)(B,QoSB)(C,QoSC)(E,QoSE):(X,QoSX):

RREPH{(X,QoSX)(H,QoSH)(E,QoSE)(C,QoSC)(B,QoSB)(S,QoSS)}

H generates a RREPH packet from RREQE & RTH

H unicasts RREPH packet to E



NS

GF

X

DB

C

E

H

Route Table(RTH)(S,QoSS)(B,QoSB)(C,QoSC)(E,QoSE):(X,QoSX):

Route Table (RTS):(B,QoSB)(C,QoSC)(E,QoSE)(H,QoSH)(X,QoSX)::

RREPH{(X,QoSX)(H,QoSH)(E,QoSE)(C,QoSC)(B,QoSB)(S,QoSS)}

RREPE{(X,QoSX)(H,QoSH)(E,QoSE)(C,QoSC)(B,QoSB)(S,QoSS)}

RREPC{(X,QoSX)(H,QoSH)(E,QoSE)(C,QoSC)(B,QoSB)(S,QoSS)}

RREPB{(X,QoSX)(H,QoSH)(E,QoSE)(C,QoSC)(B,QoSB)(S,QoSS)}

A RREP is forwarded according to the next node address S receives RREPs from neighbouring nodes S selects a suitable route based on gathered QoS of each route

NS

GF

X

DB

C

E

H

Forward Table(FTS):S->B->X:

DATAS{(S,e(ShS+S,PbB),QoSS)(B,QoSB)(C,QoSC)(E,QoSE)(H,QoSH)(X,QoSX)} FTB

:::

FTC:::

FTE:::

FTH:::

First few data packets contains full RIL S generates a ShS or keeps Shb

S unicasts DATA packet with e(ShS+S,PbB) to B

Data Transmission (1/4)

NS

GF

X

DB

C

E

H

DATAB{(S,QoSS)(B,e(ShB+B,PbC),QoSB)(C,QoSC)(E,QoSE)(H,QoSH)(X,QoSX)}FTB

:S->C->X:

Forward Table(FTS):S->B->X:

B gets ShS & S’s identification signature by d(e(ShS+S,PbB), PrB)

Registers S as a valid node matching its node identification table Updates RT/FT with unknown information Forwards data packet to the next node from RIL with e(ShB+B,PbC)


NS

GF

X

DB

C

E

HDATAC{(S,QoSS)(B,QoSB)(C,e(ShC+C,PbE),QoSC)(E,QoSE)(H,QoSH)(X,QoSX)}

FTB:S->C->X:

FTC:S->E->X:

FTE:S->H->X:

FTH:S->X->X:

DATAE{(S,QoSS)(B,QoSB)(C,QoSC)(E,e(ShE+E,PbH),QoSE)(H,QoSH)(X,QoSX)}

DATAH{(S,QoSS)(B,QoSB)(C,QoSC)(E,QoSE)(H,e(ShH+H,PbX),QoSH)(X,QoSX)}Forward Table(FTS)

:S->B->X:

Reamining nodes registers immediate upstream nodes Update RT/FT with unknown information Forward data packet to the next node from RIL with e(Sh?+?,Pb?)


Remaining data packets do not contain RIL An intermediate node

Finds the next node from the FT with <Global Source, Global Destination>

Updates Local Source with its own address Updates its RT/FT

TotalSize

Data to be TransmittedCRC

Level3Level 3

SAHNId

TypeLocal

SourceAddress

TotalSize

CRCLevel1

Level2Data

GlobalSourceAddress

GlobalDestination

Address

Level 1

Level 2 SEQ HCHTLEncrypted Level3

Payload

EncryptedLevel 3Payload

RIL(for first few

packets)

DATA Packet Format


Takes actions if

1. A link fails

2. A route error control (RERR) packet is received

3. Data packets are recieved for unknown destinations

4. A RT/FT entry becomes too old

SAHNId

TypeLocal

SourceAddress

TotalSize

CRCLevel1

GlobalSourceAddress

GlobalDestination

Address

RIL. Each node's address &QoS values

Level 1

Level 2 SEQ HCHTL

Level 2 Data

UnreachableNode

Address

RERR Packet Format

Route Maintenance (1/4)

1. If the route maintenace module senses a link failure

Tries to find alternate route to destination Sends RERR of the broken link to its neigbours Deletes corresponding entries of broken links from its

RT/FT


2. If a node receives a RERR packet the route maintenance module

Sends RERR to its neigboursDeletes corresponding entries from its RT/FT


3a. If a node receives a data packet for unknown destination, the route maintenance module

Tries to find a route to the destination

3b. If it fails, it

Sends RERR to the source of the data packet


References

A. Bickerstaffe, E. Makalic and S. Garic. CS honours

theses. Monash University.

www.csse.monash.edu.au/~rdp/SAN/. 2001 P. Misra. Routing Protocols for Ad Hoc Mobile Networks.

www.cis.ohio-state.edu/~jain/cis788-99/adhoc_routing/inde

x.html. 02/07/2000

Simulation Setup (1/2) GloMoSim (version 2.03) 21 static nodes in 3 sq. km physical terrain Standard radio model for transmission Propagation limit = -111.0 dBm Two-Ray model for the propagation path loss where

Free space path loss for direct links Plane earth path loss for more distant links

Radio transmission power = 15.0 dBm, antenna gain = 0.0 dB, radio reception threshold = -81.0 dBm, sensitivity= -91.0 dBm & SNR = 10.0 dB

AODV, DSR and SAHNR were used as routing protocols SAHNR contaied follwoing features

All standard features of DSR Network level shared key negotiation Accumulation of QoS info (available bandwidth) during route discovery Route selection based on bandwidth availabilty & hop count Using forward table for data transmission

FTP connection. 0 (Client), 11 (Server)

Total 8000000 pkts, 1460 bytes/ pkt, starts at 30 sec sim time FTP connection. 19 (Client), 1 (Server)

Total 11000 pkts, 1400 bytes/ pkt,

starts at 70 sec sim time FTP connection. 18 (Client), 3 (Server)

Total 9000000 pkts, 1500 bytes/pkt,

starts at 100 sec sim time CBR connection. 0 (Client), 20 (Server)

Total 13000000 pkts, 1512 bytes/pkt,

inter-departure time 1.5 sec/pkt,

starts at 28.8 sec sim time CBR connection. 17 (Client), 0 (Server)

Total 20000000 pkt, 1024 bytes/pkt,

inter-departure time 1.1 sec/pkt,

starts at 15 sec sim time

11

0

1

2

3

4

5

6

7

8

9

10

13

14

15

12

17

16

18

19

20

Simulation Setup (1/2)

Simulation Result (1/3)

Comparing total data received at FTP servers using SAHNR, DSR and AODV

0

20000000

40000000

60000000

80000000

100000000

0 1000 2000 3000 4000 5000Simulation Time (seconds)

Tot

al n

o. o

f byt

es r

ecei

ved

SAHNRDSRAODV

Comparing load of CTRL packets in the network

0

20000

40000

60000

80000

100000

0 1000 2000 3000 4000 5000

Simulation time (seconds)

Tot

al n

o. o

f CT

RL

pack

ets

tran

smitt

ed in

the

netw

ork

SAHNR

DSR

AODV


Comparing number of packets received with and without source routes with SAHNR

Node 0

Node 1

Node 3

Node 11Node 18

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

No. of packets received at FTP

servers

WSR - With Source Route

WOSR- Without Source Route WSRWOSR


Future worksIntegrate all QoS metrics (bandwidth, error rate,

latency, jitter) for routingIncorporate security schemes i.e. node

authentication, encryption/decryptionDefine a feasible network size & packet lengthDetect non-cooperative nodesPerform more simulations with varied network

sizes, directional antennas and different

topologies with presence of rouge nodesTest SAHNR in real environment

Acknowledgements

Initial definition of the SAHN architecture was carried out by Adrian Bickerstaffe, Enes Makalic and

Slavisa Garic in their computer science honours projects in 2001 at Monash University. They also

implemented the initial testbed. The current project builds on their excellent work.

Part of presentation was partly done with Paul Conilione, using exclusively the abilities given to him by his Chinese Buddhist Taoist Master, Shifu Chow

Yuk Nen.

Thank You

?

A Hybrid QoS Routing Strategy for Suburban Ad-Hoc Networks Muhammad Mahmudul Islam Ronald Pose Carlo Kopp School of Computer Science & Software Engineering.

Documents

sahn traffic sahn services

standard sahn node slide

sahn mit roofnet slide

sahn protocols

management slide

key slide

suburban ad

suburban area network