U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Electrical and Computer Engineering.
U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication...
-
Upload
owen-williamson -
Category
Documents
-
view
214 -
download
0
Transcript of U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication...
![Page 1: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/1.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Computer Science Department of Computer Science
R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity
Characteristics
Xiaozheng Tie, Arun Venkataramani, Aruna Balasubramanian
University of Massachusetts AmherstUniversity of Washington
![Page 2: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/2.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 2
Wireless routing compartmentalized
Protocols designed for well-connected meshes
OLSR, ETT, ETX, EDR, …
Protocols designed for intermittently-connected MANETs
AODV, DSDV, DSR, …
Protocols designed for sparsely-connected DTNs
DTLSR, RAPID, Prophet, Maxprop, EBR, Random, …
Research question: Can we design a simple routing protocol that ensures robust performance across networks with diverse connectivity characteristics all the way from well-connected meshes to mostly-disconnected DTNs and everything in between?
Research question: Can we design a simple routing protocol that ensures robust performance across networks with diverse connectivity characteristics all the way from well-connected meshes to mostly-disconnected DTNs and everything in between?
![Page 3: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/3.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 3
Outline
Compartmentalized design harmfulQuantifying replication gainR3 design and implementationEvaluationConclusion
![Page 4: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/4.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 4
Fragile performance
Protocols perform poorly outside target environment
DTN protocols perform poorly in mesh
Replication wasteful
Mesh protocols perform poorly in DTNs
No contemporaneous path
Mesh testbed DTN testbed
2.1x
Norm
aliz
ed
dela
y
2.2x
Norm
aliz
ed
dela
y
![Page 5: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/5.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 5
Spatial connectivity diversity
DieselNet-HybridVehicular DTN + Wifi Mesh20 buses in Vehicular DTN4 open AP WiFi mesh clusters
< 100 contacts
100 – 200 contacts
> 200 contacts
![Page 6: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/6.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 6
Temporal connectivity diversity
HaggleMobile ad hoc network8 mobile and 1 stationary imotes9 hour trace in Intel Cambridge Lab
Fract
ion o
f co
nnect
ed n
odes
![Page 7: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/7.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 7
Compartmentalized design harmful
Fragile performance under spatio-temporal diversity
Makes interconnection of diverse networks difficult
ManageabilitySeparation of concernsLong-term innovation
![Page 8: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/8.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 8
Outline
Compartmentalized design harmfulQuantifying replication gainR3 design and implementationEvaluationConclusion
![Page 9: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/9.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 9
Replication: Key difference
DTN MeshMANET
Sparsely connected Well connectedIntermittently connected
Replication Forwarding
Key question: Under what conditions and by how much replication improves performance?Key question: Under what conditions and by how much replication improves performance?
![Page 10: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/10.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science
Model to quantify replication gain
10
Replication gain
€
€
μ =min E[X1],E[X2],...,E[Xn ]{ }
Src
€
X1
Dst
€
X2
€
Xn
€
μ(1) = E[min{X1,X2,...,Xn}]
• Delay of forwarding
• Delay of replication
€
μμ(1)
€
X i
Random variable denoting the delay of path i
![Page 11: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/11.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 11
Example of replication gain
11
Replication gain
€
€
μ =min E[X1],E[X2]{ } =min 1,3{ } =1
Src
€
X1Dst
€
X2
€
μ(1) = E[min{X1,X2}] = 0.2
• Delay of forwarding
• Delay of replication
€
μμ(1)
= 5
€
P(X1 = 0.1) = 90%
P(X1 =10) =10%
E(X1) =1
€
P(X2 = 0.3) = 90%
P(X2 = 30) =10%
E(X2) = 3
Replication gain depends on path delay distributions, not just expected value Replication gain depends on path delay distributions, not just expected value
5x delay improvement
![Page 12: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/12.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 12
Trace-driven analysis on DieselNet-DTN and Haggle
Replication gain vs. number of paths
Vehicular DTN in DieselNet Haggle
Two paths suffice to capture much of the gainTwo paths suffice to capture much of the gain
![Page 13: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/13.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 13
Compartmentalized design harmfulQuantifying replication gainR3 design and implementationEvaluationConclusion
Outline
![Page 14: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/14.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 14
R3 design overview
Link-stateEstimate per-link delay distribution
ReplicationSelect replication paths using modelAdapt replication to be load-aware
Source routing along selected path(s)
€
Y1
€
Y2
€
Y3
Src Dst
![Page 15: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/15.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 15
Link delay
Estimate link delay using periodic probes
Estimate link delay distribution
Time
30s20s
10s0.1s
Link availability delay Delay to successfully transfer pkt
Delay samples = {30.1s, 20.1s, 10.1s}
Acked probe Half of round-trip delay
Unacked probe Half of time since sending probe and
receiving an ack for subsequent probe
![Page 16: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/16.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 16
R3 design overview
Src Dst
Link-stateEstimate per-link delay distribution
ReplicationSelect replication paths using modelAdapt replication to be load-aware
Source routing along selected path(s)
![Page 17: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/17.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 17
First pathPath s.t. it minimizes Selected using Dijkstra’s shortest path algorithm
Second pathPath s.t. it minimizesSelected using delay distributions and model
Path selection using model
€
k( ∈{1,2,...,n})
€
E[Xk ]
€
E[min{X i,Xk}]
€
k( ∈{1,2,...,n})
€
X1
€
X2
€
Xn€
X iSrc Dst
€
i
€
j
![Page 18: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/18.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 18
ProblemReplication hurts performance under high load
SolutionLoad aware replication
Adapting replication to load
ForwardingForwardingReplicationReplicationStart
actual_delay > 2 * model_estimated_delay
actual_delay ≤ 2 * model_estimated_delay
![Page 19: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/19.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 19
R3 design overview
Link-stateEstimate per-link delay distribution
ReplicationSelect replication paths using modelAdapt replication to be load-aware
Source routing along selected path(s)
Src Dst
![Page 20: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/20.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 20
Compartmentalized design harmfulQuantifying replication gainR3 design and implementationEvaluation
Deployment on a DTN and mesh testbedSimulation based on real tracesEmulation using mesh testbed
Conclusion
Outline
![Page 21: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/21.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 21
DieselNet DTN testbed20 buses in a 150 sq. mile area
Mesh testbed16 nodes in one floor
Simulator validation using DieselNet deployment
< 10% of deployment result
R3 Deployment
![Page 22: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/22.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 22
Experimental settingsTemporal diversity inherent in HaggleSpatial diversity inherent in DieselNet-HybridVarying load
Compared protocolsReplication: RAPID, RandomForwarding: DTLSR, AODV, OLSRMulti-configuration: SWITCH (RAPID+OLSR)
R3 Trace-driven simulation
![Page 23: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/23.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science
Robustness to spatial diversity
Simulation based on DieselNet-Hybrid trace
23
R3 improves median delay by 2.1xR3 improves median delay by 2.1x
1
2
34
5
6
7
8
9
![Page 24: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/24.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science
Robustness to varying load
Simulation based on DieselNet-Hybrid trace
24
R3 reduces delay by up to 2.2x over SWITCHR3 reduces delay by up to 2.2x over SWITCH
![Page 25: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/25.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 25
Compartmentalized design harmful
R3 ensures robust performance across diverse connectivity characteristics
Unified link metric based on delay distributionsReplication based on delay uncertainty modelAdaptive replication based on network load
Conclusion
![Page 26: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/26.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science
Q&A
26
![Page 27: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/27.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 27
Theorem: Replication gain is high iff path delays are highly unpredictable
Predictability of a random variable X = Smallest such that
When is replication gain high?
€
ε
€
P[X ≤ εE[X]] ≥1−ε
Corollary: Replication can yield unbounded gain even with two pathsCorollary: Replication can yield unbounded gain even with two paths
![Page 28: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/28.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science 28
Path delay Expected delay: Delay distribution of : convolutions of
Estimating path delay distribution
€
Y1
€
Yi
€
Y2
€
Yn
€
X
€
E[X] = E[Y1]+ E[Y2]+ ...+ E[Yn ]
€
X =Y1 +Y2 + ...+Yn
€
Y1,Y2,...,Yn
€
X
Link delay distribution Path delay distribution
![Page 29: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/29.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science
Robustness to temporal diversity
Simulation based on Haggle trace
29
R3 reduces delay by up to 60%R3 reduces delay by up to 60%
R3 increases goodput by up to 30%R3 increases goodput by up to 30%
![Page 30: U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Computer Science R3: Robust Replication Routing in Wireless Networks with Diverse Connectivity Characteristics.](https://reader036.fdocuments.in/reader036/viewer/2022070305/5514da1655034640138b64f5/html5/thumbnails/30.jpg)
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS A AMHERST • MHERST • Department of Computer Science Department of Computer Science
Emulating intermediate connectivity
Mesh-based emulation approach Brings link up and down
to vary connectivity Emulates connectivity
diversity (but not mobility)
30
R3 reduces delay by up to 2.2xR3 reduces delay by up to 2.2x