A Framework for the Management of Large-Scale Wireless Network Testbeds

1
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

2
Growing Testbed Deployment

• Experimental research crucial in the design of
  robust wireless networking systems
• Thus, wireless testbeds are being increasingly
  deployed
• Examples MIT Roofnet, Great Duck Island, UCSB
  MeshNet, Orbit

3
Testbed Management

• Maintaining Testbeds can be Extremely
  Labor-Intensive
• Nature of wireless medium makes management
  challenging
• Bugs or design flaws can crash the entire network
• Best Current Practice?
• Manual intervention through maintenance of
  devices on-site
• Labor-intensive
• In-band management
• Prevents certain testbed changes
• 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

4
Testbed Management

• Best Current Practice? (cont'd)
• Out-of-band management offers substantial relief
• Typically performed via wired backhaul network
• Not always feasible!
• Logistical/Bureaucratic issues (Ex UCSB MeshNet)
• Large or inhospitable testbed area (Ex Rooftop
  Nets)
• Our solution out-of-band management via a
  multi-hop wireless mesh network

5
Proposed Solution

• Wireless multi-hop mesh backhaul for out-of-band
  management
• Maturing mesh networking technology provides
  stable backhaul
• Cheap
• Easy to deploy

6
Outline

• Motivation
• ATMA Framework
• Self-Configuring Architecture
• ATMA Management Tools
• Implementation Overview
• Conclusions

7
ATMA Framework

• Enables out-of-band mgt of large-scale testbeds
• Distributed agent-manager architecture
• Self-configuring architecture
• Extensions of basic framework for management of
  multi-hop wireless testbeds
• Proof-of-concept using Linksys WRT54G devices

8
Self-Configuring Architecture

• Manager Beaconing
• 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 Boot-Strapping
• Agent listen for beacons by scanning all 802.11
  channels
• Pick temporary IP address to communicate with
  manager
• Agent Registration
• Agents register with manager
• Manager issues appropriate instructions to agents

9
ATMA Management Tools

• Testbed Configuration Tool
• Agents configure testbed nodes as per
  instructions from manager
• Interference Meter
• Listens for IEEE Management frames
• Count of unique MAC IDs gives estimate of
  interference level
• Network Monitoring Using DAMON
• Generic monitoring tool for collection of
  topology data, data traffic statistics, routing
  protocol statistics
• http//moment.cs.ucsb.edu/damon/
• Topology Control Tool
• Creates virtual topologies without physically
  moving nodes
• Uses selective dropping of packets to create
  virtual topology

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Implementation Overview

• Proof-of-concept implemented using Linksys WRT54G
  wireless devices
• Low-cost solution
• Uses OpenWRT open-src firmware (www.openwrt.org)
• Uses multi-path version of AODV
• Reliability-based metric for route selection
• ATMA Management tools using Perl/C

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Conclusions

• ATMA enables the out-of-band management of
  large-scale wireless testbeds
• Self-configuring architecture enables quick and
  easy deployment of support mesh network
• ATMA extensions for multi-hop wireless testbeds
• Proof-of-concept using cheap commodity devices
• Plan to offer framework as free download in the
  future

12
Questions?