Download A Hybrid QoS Routing Strategy for Suburban Ad

A Hybrid QoS Routing
Strategy for
Suburban Ad-Hoc Networks
Muhammad Mahmudul Islam
Ronald Pose
Carlo Kopp
School of Computer Science & Software Engineering
Monash University
Outline
Introduction
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Acknowledgements
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 etc
Local Telephone
Office
Local
Telephone
Office
ISP
Local
Telephone
Office
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
Application
Application
SAHN services
Presentation
Pre se ntation
run alongside
Se ssion
S ession
A V
O
U
E
T
TCP/UDP
TCP/UDP
TCP/IP
Transport
Transport
D D
H
I
I
E
IP
Conceived by
O O R
IP
Ne twork
Network
SAHN Routing
Ronald Pose
Data Link
e .g. IEEE 802.11 variants
Data Link
&
Physical
e .g. IEEE 802.11 variants
Physical
Carlo Kopp in 1997
A Standard SAHN Node





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
References
 R. Pose and C. Kopp. Bypassing the Home Computing
Bottleneck: The Suburban Area Network. 3rd Australasian
Comp. Architecture Conf. (ACAC). February, 1998. pp.87100.
 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 to
Eavesdropping
DoS attacks
Node masquerading
Requires security policies implemented at all levels
Wireless technologies (e.g. 802.11) do not feature
Resource access control
Resource 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)
Ad-Hoc Routing Protocols
Table
Driven
DSDV
WRP
GSP
FSR
HSR
On
Demand
DSR
AODV
MSR
AOMDV
TORA
Hybrid
LANMAR
QoS
Routing
Possible Routing Solutions for SAHN (2/3)
Dynamic source routing (DSR)
 On demand
 Uses source routing
 Can find multiple routes
 Network overhead increases for carrying
source routes
 No security at network layer
 Does not consider QoS for route selection
 Does not feature load balancing
 Cannot detect non-cooperating nodes
Possible Routing Solutions for SAHN (3/3)
Ad Hoc on demand distance vector (AODV) routing
 On demand
 Cannot find multiple routes to a destination
 No security at network layer
 Does not consider QoS for route selection
 No support for load balancing
 Cannot detect non-cooperating nodes
Why Customized Routing for SAHN (1/2)
Existing ad-hoc routing solutions do not feautrure
one or more of the following attributes
 Multiple routes to a destination
 Resource Access Control
 QoS
 Load balancing
 Security at network layer
 Optimization for quasi-static networks
 Handling non-cooperating nodes
Why Customized Routing for SAHN (2/2)
Mobile IP (IPv6)
 Uses proactive routing technique ideal for
centralized networks
 Whole network is flooded with link state
information
 Assumes direct link (single hop) between
home/foreign agent and each host
 Cannot not handle non-cooperating nodes
Properties of SAHN Routing Protocol (1/2)
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 (2/2)
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
Focus of this Paper
Modified 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 SAHNR
Available 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 keys
are done in these phases
Network Level Security at a Glance
 RREQ packets contain
1. Public key
from downstream nodes
 ACKRREQ packets contain
1. Public key
from upstream nodes
2. Shared key
3. Identification signature
1 & 2 are encrypted with down stream nodes’ public key
 Initial DATA packet for a session contains
1. Shared key
from downstream nodes
2. Identification signature
1& 2 are encrypted with upstream nodes’ public key
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

Level 1
Level 2
Global
Source
Address
SAHN
Id
Type
Global
Destination
Address
Local
Source
Address
SEQ
HTL
Total
Size
Level 2 Data
HC
RIL. Each node's address &
QoS values
RREQ/RREP Packet Format
CRC
Level1
Public key of the
transmitting node
(for RREQ)
Neighbour Discovery & Security (2/8)


S wants to find route to X
Generates [public key (PbS), private key(PrS)]
D
B
H
C
S
N
G
E
F
X
Neighbour Discovery & Security (3/8)

S broadcasts RREQS packets to its neighbours with PbS
RREQS
{S,PbS,QoSS}
D
B
H
C
S
N
RREQS
G
E
F
X
Neighbour Discovery & Security (4/8)


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
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
ACKRREQ B
{e(ShB+B,PbS),
PbB}
RREQB
{(S,QoSS)
(B,PBB,QoSB)}
B
RREQB
S
H
C
N
G
D
E
F
X
Neighbour Discovery & Security (5/8)


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
B
ACKRREQC
{e(ShC+C,PbB), PbC}
C
S
N
G
RREQC
{(S,QoSS)(B,QoSB)
(C,PBC,QoSC)}
RREQC RREQ
C
F
D
E
H
X
Neighbour Discovery & Security (6/8)


H receives RREQE from E
H has route to X
D
B
H
C
S
N
ACKRREQE
G
F
E
RREQE
Route Table(RTH)
:
:
(X,QoSX)
:
RREQE
{(S,QoSS)
(B,QoSB)
(C,QoSC)
(E,PbE,QoSE)}
X
Neighbour Discovery & Security (7/8)


H generates a RREPH packet from RREQE & RTH
H unicasts RREPH packet to E
D
B
H
C
S
N
Route
Table(RTS)
:
:
:
G
E
F
Route Table(RTH)
(S,QoSS)(B,QoSB)
(C,QoSC)(E,QoSE)
:
(X,QoSX)
:
X
RREQE
{(S,QoSS)
(B,QoSB)
RREPH
(C,QoSC)
{(X,QoSX) (E,QoSE)}
(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
Neighbour Discovery & Security (8/8)



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
RREPB
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
B
RREPC
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
C
S
Route Table (RTS)
:
(B,QoSB)(C,QoSC)
(E,QoSE)(H,QoSH)
(X,QoSX)
:
:
G
N
D
RREPE
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
E
F
H
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)}
X
Data Transmission (1/4)



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
DATAS
{(S,e(ShS+S,PbB),QoSS)
(B,QoSB)(C,QoSC)
(E,QoSE)(H,QoSH)
(X,QoSX)}
FTB
:
:
:
D
B
S
Forward Table(FTS)
:
S->B->X
:
G
N
FTH
:
:
:
FTC
:
:
:
H
C
E
F
FTE
:
:
:
X
Data Transmission (2/4)




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)
B
S
FTB
:
S->C->X
:
Forward Table(FTS)
:
S->B->X
:
G
DATAB
{(S,QoSS)
(B,e(ShB+B,PbC),QoSB)
(C,QoSC)(E,QoSE)
(H,QoSH)(X,QoSX)}
D
H
C
N
E
F
X
Data Transmission (3/4)



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?)
D
B
S
FTB
:
S->C->X
:
Forward Table(FTS)
:
S->B->X
:
G
N
FTH
:
S->X->X
:
C
FTC
:
S->E->X
:
F
DATAC
{(S,QoSS)(B,QoSB)
(C,e(ShC+C,PbE),QoSC)
(E,QoSE)(H,QoSH)
(X,QoSX)}
E
FTE
:
S->H->X
:
H
X
DATAH
{(S,QoSS)(B,QoSB)
(C,QoSC)(E,QoSE)
(H,e(ShH+H,PbX),QoSH)
(X,QoSX)}
DATAE
{(S,QoSS)(B,QoSB)
(C,QoSC)
(E,e(ShE+E,PbH),QoSE)
(H,QoSH)(X,QoSX)}
Data Transmission (4/4)
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
Level 1
Level 2
SAHN
Id
Global
Source
Address
Type
Local
Source
Address
Global
Destination
Address
Total
Size
SEQ
Level 3
HTL
Total
Size
Level2
Data
HC
Encrypted
Level 3
Payload
RIL
(for first few
packets)
Data to be Transmitted
DATA Packet Format
CRC
Level1
Encrypted Level3
Payload
CRC
Level3
Route Maintenance (1/4)
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
Level 1
Level 2
SAHN
Id
Type
Global
Source
Address
Local
Source
Address
Global
Destination
Address
Total
Size
SEQ
Level 2 Data
HTL
HC
Unreachable
Node
Address
RERR Packet Format
CRC
Level1
RIL. Each node's address &
QoS values
Route Maintenance (2/4)
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 (3/4)
2. If a node receives a RERR packet the route
maintenance module
Sends RERR to its neigbours
Deletes corresponding entries from its RT/FT
Route Maintenance (4/4)
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
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/cis78899/adhoc_routing/index.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
Simulation Setup (1/2)





FTP connection. 0 (Client), 11 (Server)
Total 8000000 pkts, 1460 bytes/ pkt, starts at 30 sec sim time
FTP connection. 19 (Client), 1 (Server)
0
7
Total 11000 pkts, 1400 bytes/ pkt,
starts at 70 sec sim time
4
FTP connection. 18 (Client), 3 (Server)
Total 9000000 pkts, 1500 bytes/pkt,
1
8
starts at 100 sec sim time
CBR connection. 0 (Client), 20 (Server)
5
Total 13000000 pkts, 1512 bytes/pkt,
inter-departure time 1.5 sec/pkt,
2
9
starts at 28.8 sec sim time
CBR connection. 17 (Client), 0 (Server)
6
Total 20000000 pkt, 1024 bytes/pkt,
inter-departure time 1.1 sec/pkt,
3
10
starts at 15 sec sim time
14
11
18
15
12
19
16
13
20
17
Simulation Result (1/3)
Total no. of bytes received
Comparing total data received at FTP servers using
SAHNR, DSR and AODV
100000000
80000000
60000000
40000000
20000000
0
SAHNR 0
DSR
AODV
1000 2000 3000 4000
Simulation Time (seconds)
5000
Simulation Result (2/3)
Total no. of CTRL packets
transmitted in the network
Comparing load of CTRL packets in the network
100000
80000
60000
40000
20000
0
SAHNR
DSR
AODV
0
1000
2000
3000
Simulation time (seconds)
4000
5000
Simulation Result (3/3)
Comparing number of packets received with and without
source routes with SAHNR
100000
90000
80000
70000
No. of packets
received at FTP
servers
60000
50000
40000
Node 18
Node 11
30000
20000
Node 3
10000
WSR - With Source Route
WOSR- Without Source Route
Node 1
0
Node 0
WSR
WOSR
Future works
Integrate all QoS metrics (bandwidth, error rate,
latency, jitter) for routing
Incorporate security schemes i.e. node
authentication, encryption/decryption
Define a feasible network size & packet length
Detect non-cooperative nodes
Perform more simulations with varied network
sizes, directional antennas and different
topologies with presence of rouge nodes
Test 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
?