a hybrid qos routing strategy for suburban ad-hoc networks muhammad mahmudul islam ronald pose carlo...
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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
Possible Routing Solutions for SAHN (2/3)
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
Possible Routing Solutions for SAHN (3/3)
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
Neighbour Discovery & Security (2/8)
S broadcasts RREQS packets to its neighbours with PbS
NS
G
H
FE
X
D
C
BRREQS{S,PbS,QoSS}
RREQS
Neighbour Discovery & Security (3/8)
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
Neighbour Discovery & Security (4/8)
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
Neighbour Discovery & Security (5/8)
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
Neighbour Discovery & Security (6/8)
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
Neighbour Discovery & Security (7/8)
Neighbour Discovery & Security (8/8)
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)
Data Transmission (2/4)
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?)
Data Transmission (3/4)
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
Data Transmission (4/4)
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
Route Maintenance (2/4)
2. If a node receives a RERR packet the route maintenance module
Sends RERR to its neigboursDeletes corresponding entries from its RT/FT
Route Maintenance (3/4)
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
Route Maintenance (4/4)
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
Simulation Result (2/3)
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
Simulation Result (3/3)
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.