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A Framework for the
Management of Large-Scale
Wireless Network Testbeds
Krishna Ramachandran,
Kevin C. Almeroth, Elizabeth Belding-Royer
Dept of Computer Science,
UC Santa Barbara
WinMee 2005
Growing Testbed Deployment
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Experimental research crucial in the design of
robust wireless networking systems
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Thus, wireless testbeds are being increasingly
deployed
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Examples: MIT Roofnet, Great Duck Island, UCSB
MeshNet, Orbit
WinMee 2005
Testbed Management
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Maintaining Testbeds can be Extremely Labor-Intensive
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Nature of wireless medium makes management challenging
Bugs or design flaws can crash the entire network
Best Current Practice?
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Manual intervention through maintenance of devices on-site
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Labor-intensive
In-band management
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Prevents certain testbed changes
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Ex: Switching frequency of a multi-hop wireless network testbed
Node failure can leave entire network disconnected
In-band management adds overhead to traffic in testbed
WinMee 2005
Testbed Management
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Best Current Practice? (cont'd)
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Out-of-band management offers substantial relief
Typically performed via wired backhaul network
 Not always feasible!
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Logistical/Bureaucratic issues (Ex: UCSB MeshNet)
Large or inhospitable testbed area (Ex: Rooftop Nets)
Our solution: out-of-band management via a multihop wireless mesh network
WinMee 2005
Proposed Solution
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Wireless multi-hop mesh
backhaul for out-of-band
management
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Maturing mesh networking
technology provides stable
backhaul
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Cheap
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Easy to deploy
WinMee 2005
Outline
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Motivation
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ATMA Framework
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Self-Configuring Architecture
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ATMA Management Tools
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Implementation Overview
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Conclusions
WinMee 2005
ATMA Framework
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Enables out-of-band mgt of large-scale testbeds
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Distributed agent-manager architecture
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Self-configuring architecture
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Extensions of basic framework for management of
multi-hop wireless testbeds
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Proof-of-concept using Linksys WRT54G devices
WinMee 2005
Self-Configuring Architecture
1.
Manager Beaconing
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2.
Agent Boot-Strapping
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3.
Hop-by-hop propagation of mgr beacons throughout
network
Helps agents automatically discover the manager
Helps to resolve 802.11 BSSID problem in mesh networks
Agent listen for beacons by scanning all 802.11 channels
Pick temporary IP address to communicate with manager
Agent Registration
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Agents register with manager
Manager issues appropriate instructions to agents
WinMee 2005
ATMA Management Tools
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Testbed Configuration Tool
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Interference Meter
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Listens for IEEE Management frames
Count of unique MAC IDs gives estimate of interference level
Network Monitoring Using DAMON
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Agents configure testbed nodes as per instructions from manager
Generic monitoring tool for collection of topology data, data traffic
statistics, routing protocol statistics
http://moment.cs.ucsb.edu/damon/
Topology Control Tool
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Creates virtual topologies without physically moving nodes
Uses selective dropping of packets to create virtual topology
WinMee 2005
Implementation Overview
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Proof-of-concept implemented using Linksys WRT54G
wireless devices
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Low-cost solution
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Uses OpenWRT open-src firmware (www.openwrt.org)
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Uses multi-path version of AODV
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Reliability-based metric for route selection
ATMA Management tools using Perl/C
WinMee 2005
Conclusions
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ATMA enables the out-of-band management of largescale wireless testbeds
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Self-configuring architecture enables quick and easy
deployment of support mesh network
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ATMA extensions for multi-hop wireless testbeds
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Proof-of-concept using cheap commodity devices
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Plan to offer framework as free download in the future
WinMee 2005
Questions?
WinMee 2005