Download Efficient Routing in Suburban Ad-Hoc Networks

First Page
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Current Project Status
Acknowledgements
Index1
An alternative to
existing broadband
services for
cooperative users
using wireless
technology at an
affordable cost
Definition1
SAHN
Definition
Dialup and high speed services (e.g. cable
modems & xDSL)
• Provide mostly asymmetric bandwidth
utilization
• Inadequate for file transfer, X protocol,
interactive graphical programs etc
• Require costly wiring infrastructure
• Impose service charges
• Not widely available
Why not existing
solutions1
Nokia RoofTop and other packet radio
schemes
• Mostly centrally controlled
• Provide inadequate QoS
• Not optimized for Ad-Hoc networks
Why not existing
solutions2
• Commercial broadband solutions are:
– Expensive
– Not universally available
– Provide restricted service
• Commercial service restrictions:
– Asymmetric traffic characteristics
– Poor QoS management
– Only supports Internet protocols
– Limited security, management and
accounting support
SAHN
Motivation
• Provide 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
Telcos independent traffic
Motivation
• Feature QoS
• 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
• Proper resource access control and
management
Motivation2
• Ideal for cooperative nodes. E.g. spread over a
suburban area, connecting houses and business
•
•
•
•
•
Topology is quasi static
Uses wireless technology
Multi-hop QoS routing
Decentralized
Symmetric broadband, multi Mbits/sec
bandwidth
• Security
SAHN
Definition
• No charges for SAHN traffic
• SAHN services Application
Presentation
run alongside
Session
TCP/UDP
TCP/IP
Transport
• Conceived by
Network
IP
Ronald Pose &
Data Link
Carlo Kopp
Physical
SAHN Definitio2
Application
Presentation
Session
Transport
TCP/UDP
IP
Network
A
U
D
I
O
V
E
D
I
O
SAHN
Data Link
e.g. IEEE 802.11 variants
Physical
e.g. IEEE 802.11 variants
O
T
H
E
R
• Home office and professionals requiring
broadband connection to organisation’s
systems
• Internetworking of businesses with their
offices spread through a suburb, campus
buildings etc
• People living around their campus can
access the university’s network via SAHN
without expensive commercial Telecom
services
Who should be using
• Cooperative users can communicate and
share a speedy Internet connection with
each other via SAHN
• Houses linked with video clubs can
download video streams on demand
• Groups with online gaming interests
Users2
• Appears to host like a cable modem
• Functionally more like a
RF LAN repeater
• Embedded
microprocessor
protocol engine
implements all SAHN protocols and manages
and configures the system
• Each SAHN node has at least 2 wireless links
• Capable of achieveing link rate throughput
Standalone
SAHN
•
•
•
•
Investigating wireless technology
An appropriate routing solution
A robust node authetication scheme
Appropriate security models for various
layers
• Integrating SAHN specific hardware and
software solutions at minimum cost
• A suitable business model for exploiting the
SAHN concept
SAHN
Issue1
•
•
•
•
Investigating wireless technology
An appropriate routing solution
A robust node authetication scheme
Appropriate security models for various
layers
• Integrating SAHN specific hardware and
software solutions at minimum cost
• A suitable business model for exploiting the
SAHN concept
Design Issues2
• 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
References1
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Current Project Status
Acknowledgements
Index2
• 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
– Management
Requires higher level protocols
SAHN
Goals
• Ad-Hoc wireless networks have to
– Handle node/link failures
– Find routes on demand
– Route packets with QoS
Requires an efficient on-demand routing
solution
SAHN Goals
• Table Driven
– Maintains multiple tables for route information
– Constant overhead for routing control packets
– e.g. DSDV, WRP, GSP, FSR, HSR
• On Demand
– Finds routes on demand
– Reduced overhead of routing control packets
– e.g. AODV, DSR, AOMDV, MSR, TORA, ABR
Existing
Routing0
• Hybrid
– Employes both table driven and on
demand routing techniques
– e.g. LANMAR
• Others
– Ensures QoS routing
– Can be any of the above three types
Existing Routing1
• Dynamic source routing (DSR)
– On demand
– Emplyes 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
Existing
Routing1
• Ad Hoc on demand distance vector routing
(AODV)
– 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
Existing
Routing1
Existing 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
Why Hybrid
Approach1
• Keeps up-to-date neighbour information
• Employs source routing for route discovery
• Maintains routes dynamically
– Employs features of DSR.
e.g. gratuitous Route replies,
salvaging data/error packets etc.
SAHNR1
• 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 by
– Node authentication
– Encryption of packet header information
SAHNR1
• Neighbour Discovery and Authentication
Periodically and on demand
• Route Discovery
On demand
• Data Transmission
On demand
• Route Maintenance
Periodically and on demand
SAHNR2
Performed
– When a node is powered up
– After an idle period if needed
Main tasks are
– Node authentication
– Negotiation of security scheme for network layer
Requires
– ‘Hello’/‘Hello Reply’ packets
SAHN
Id
Type
Local
Source
Address
Total
Size
Encrypted
Level2 Payload
CRC
Level1
Level 1
Level 2
Neighbor
Discovery1
Transmission
Time (TT)
Shared
key
Node N wants to join SAHN
D
B
C
S
N
G
Nehbourhood
Discovery2
H
E
F
X
N Generates a
Shared Key for
encryption
during
transmitting
data to
neighbors
Encrypts level 2
payload using
own Secret Key
& generates
cipher text C1
Nehbourhood
Discovery2
Encrypts C1
using SAHN
Public Key &
generates
cipher text C2
Prepends C2
with the
remaining
`Hello'packet
Node N broadcasts Hello packets and S,
B, C, F, G receive them
D
B
Hello
S
Hello
N
Hello
G
Nehbourhoo
d
H
C
Hello
Hello
E
F
X
`Hello' packet?
No
Processes
for other
packet types
Yes
Deciphers C2 by
SAHN Secret Key
& generates C1
Searches the
Not
distributed and secured key
Found
database for N's
Discards
Public Key
the invalid
Found
packet
Deciphers
C1 using
Node N's
Public Key
Registers N as a
valid SAHN
node. The
Shared Key is
saved for future
encryption/
decryption of
level 2 header of
the sent/received
packets.
Neighbor
Discovery3
Nodes S, B, C, F and G unicast Hello Reply
packet to N
D
B
Reply
S
Reply
N
Reply
G
H
C
X
Reply
E
Reply
F
Neighbor
Discovery3
Now node N becomes a part of SAHN
D
B
C
S
N
G
Neighbor
Discovery3
H
E
F
X
• Performed if
– Route is not present in routing table
– Route has expired
• Requires
– RREQ and RREP packets
• Uses negotiated encrytion/decryption key for
RREQ/RREP packet encrytion/decryption
Level 1
SAHN
Id
Level 2
Transmission
Time (TT)
Route
Discovery1
Type
Local
Source
Address
Global
Source
Address
Total
Size
Global
Destination
Address
Encrypted
Level2
Header
SEQ
Level 2 Data
HTL
HC
CRC
Level1
RAQL. Each node's
address & QoS values
S wants route to X. S broadcasts
RREQ packets to its neighbours
RREQ
(S,QoSS)
B
H
C
S
RREQ
(S,QoSS)
G
Route
Discovery2
D
N
E
F
X
Intermediate Nodes e.g. B does not have a
route to Node X
– B updates its routing table/forwarding table
with unknown information
– Appends its address and QoS information
in RAQL
– Broadcasts RREQ to its neighbours
Route
Discovery2
RAQL={
(S,QoSS)}
B
D
H
C
S
RREQ
(S,QoSS)
G
Route
Discovery2
RAQL={
(S,QoSS)
(B,QoSB)}
N
E
F
Route Table
:
:
(X,QoSX)
:
RAQL={
(S,QoSS)
(B,QoSB)
(C,QoSC)
(E,QoSE)}
X
• Intermediate node H has routes to X
– H updates its routing/forwarding table with
unknown information
– Appends H and QoSH with RAQL
– Appends route to X and QoS information
with RAQL
– Reverses RAQL
– Forwards RREP to E from RAQL
• Same steps for X if it receives a RREQ
Route
Discovery3
D
B
C
S
N
Route Table
:
:
:
G
Route Discovery3
H
E
F
Route Table
(S,QoSS)(B,QoSB)
(C,QoSC)(E,QoSE)
:
(X,QoSX)
:
X
RAQLE
{(S,QoSS)
(B,QoSB)
RAQLH
(C,QoSC)
{(X,QoSX) (E,QoSE)}
(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
• Intermediate Nodes receive RREP packets
– Update their routing/forwarding tables
– Update QoS values of RAQL
– Forward RREP
• Node S receives RREP packets
– Updates its routing/forwarding table
– Records routes
– Selects suitable routes with acceptible
QoS to send data
Route
Discovery4
RAQLB
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
B
C
S
Route Table
:
(B,QoSB)(C,QoSC)
(E,QoSE)(H,QoSH)
(X,QoSX)
:
:
G
Route
Discovery4
RAQLC
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
N
D
RAQLE
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
E
F
H
Route Table
(S,QoSS)(B,QoSB)
(C,QoSC)(E,QoSE)
:
(X,QoSX)
:
RAQLH
{(X,QoSX)(H,QoSH)
(E,QoSE)(C,QoSC)
(B,QoSB)(S,QoSS)}
X
• First few data packets contains full RAQL
• An intermediate node
– Updates its routing/forwarding tables with
unknown information
– Forwards data packet to the next node from RAQL
Level 1
SAHN
Id
Type
Local
Source
Address
Total
Size
Encrypted
Level2
Header
Encrypted
Level 3
Payload
CRC
Level1
Level 2
Transmission
Time (TT)
Data
Transmission1
Global
Source
Address
Global
Destination
Address
SEQ
HTL
Level 3
Total
Size
HC
RAQL
Encrypted Level3
Payload
Data to be Transmitted
CRC
Level3
• Remaining data packets do not contain RAQL
• An intermediate node
– Finds the next node from the forwarding table
with <Global Source, Global Destination>
– Updates Local Source with its own address
– Updates its routing/forwarding tables
Level 1
SAHN
Id
Type
Local
Source
Address
Total
Size
Encrypted
Level2
Header
Encrypted
Level 3
Payload
CRC
Level1
Level 2
Transmission
Time (TT)
Data
Transmission2
Global
Source
Address
Global
Destination
Address
SEQ
HTL
Level 3
Total
Size
HC
Encrypted Level3 Payload
Data to be Transmitted
CRC
Level3
Takes actions if
• A link fails
• A route error control packet is received
• Data packets are recieved for unknown
destinations
• A neighbour/route/forward table entry is too old
Level 1
Level 2
Route
Maintenance1
SAHN
Id
Transmission
Time (TT)
Type
Global
Source
Address
Local
Source
Address
Global
Destination
Address
Total
Size
SEQ
Encrypted
Level2
Header
HTL
HC
Level 2 Data
Unreachable
Node
Address
CRC
Level1
RAQL. Each node's
address & QoS values
If the route maintenace module senses a link
failure, it
• Tries to find alternate route to destination
• Sends RERR of the broken link to its
neigbours
• Deletes corresponding entries of broken links
from its neighbour/route/forward tables
Route
Maintenance2
If a node receives a RERR packet the route
maintenance module
– Sends RERR to its neigbours
– Deletes corresponding entries from its
neighbour/route/forward tables
Level 1
Level 2
Route
Maintenance3
SAHN
Id
Transmission
Time (TT)
Type
Global
Source
Address
Local
Source
Address
Global
Destination
Address
Total
Size
SEQ
Encrypted
Level2
Header
HTL
HC
Level 2 Data
Unreachable
Node
Address
CRC
Level1
RAQL. Each node's
address & QoS values
If a node receives a data packet for
unknown destination, the route maintenance
module
– Tries to find a route to the destination
If it fails, it
– Sends RERR to the source of the data
packet
Route
Maintenance4
• 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
Referenc
e2
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Current Project Status
Acknowledgements
Index2
• Node 0 sends node 11 8000 items of 1460 bytes each between simulated
times 30 sec to 10 hr through FTP.
• Node 11 sends node 0 11000 items of 1400 bytes each between
simulated times 70 sec to 10 hr through FTP.
• Node 12 sends node 13 9000 items of 1500 bytes each between
simulated times 100 sec to 10 hr through FTP.
• Node 0 sends node 11 13000 items of 512 bytes each between simulated
times 15 sec to 10 hr. The inter departure time for
13
14
15
each item is 3.1 sec.
• Node 11 sends node 0 20000 items of 1024 bytes
each between
6
7
8
9
10
16
simulated times
28.8 sec to 10 hr.
11
12
17
The inter departure 0
time for each
item is 1.5 sec.
1
2
3
4
5
Simulation
Setup
Comparing data reception rates at FTP server 11 at normal condition
session duration for SAHNR
session duration for DSR
session duration for AODV
No of bytes
received
14000000
12000000
10000000
8000000
6000000
4000000
2000000
0
SAHNR
DSR
AODV
Simulation
Result1
0
500
1000
Simulation time (second)
1500
2000
Comparing data reception rates at FTP server 11 when a node periodically
switches off and on
session duration for SAHNR
session duration for DSR
No of bytes
received
session duration for AODV
14000000
12000000
10000000
8000000
6000000
4000000
2000000
SAHNR
DSR
AODV
Simulation Result
2
0
0
500
1000
Simulation time (second)
1500
2000
Comparing load of CTRL packets in the network at normal condition
No of CTRL packtes
transmitted
14000
12000
10000
8000
6000
4000
2000
0
SAHNR
DSR
AODV
Simulation
0
1000
2000
3000
Simulation time (second)
4000
5000
No of CTRL packets
transmitted
Comparing load of CTRL packets in the network when a node periodically
switches off and on
20000
15000
10000
5000
SAHNR
DSR
AODV
Simulation Result4
0
0
1000
2000
3000
Simulation time (second)
4000
5000
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Current Project Status
Acknowledgements
Index4
• Integrate all QoS metrics (bandwidth
reservation, error rate, latency) 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, different topologies with presence of
rouge nodes
• Test SAHNR in real environment
Future
works
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Current Project Status
Acknowledgements
Index5
• Eliminated the use of Hello & Hello Reply
cycles for node authentication
• Incorporated authentication scheme with route
discovery cycle
• Performed more simulations with different
network topology
Current status
Three more papers in press to be published
• Routing In Suburban Ad-Hoc Networks
The 2003 International Conference on Computer
Science and its Applications (ICCSA’03)
• A Hybrid QoS Routing Strategy for Suburban AdHoc Networks
The 11th IEEE International Conference on Networks
(ICON’03)
• A Router Architecture To Achieve Link Rate
Throughput In Suburban Ad-Hoc Networks
The Eighth Asia-Pacific Computer Systems
Architecture Conference (ACSAC’03)
Current status2
Overview of SAHN
Routing in SAHN (SAHNR)
Simulation Results
Future Work
Current Project Status
Acknowledgements
Index
6
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 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
Acknowled
gements