Transcript Slides - TERENA> Events> tnc2006

A WAN-in-LAB for
Protocol Development
Netlab, Caltech
George Lee, Lachlan Andrew, David Wei,
Bartek Wydrowski, Cheng Jin,
John Doyle, Steven Low, Harvey Newman
Outline
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What and why WAN-in-Lab?
Current projects
Equipment
Configuration
External connections
Future plans
How can I get access to WAN-in-Lab?
What is WAN-in-Lab?
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“Wide Area” Network in a laboratory
• Real fibre delays
• Carrier-class routers, switches, …
Why -- Spectrum of tools
cost
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UltraLight
PlanetLab
Abilene
NLR
LHCNet
CENIC
etc
DummyNet
EmuLab
ModelNet
NS2
WAIL
SSFNet
QualNet
JavaSim
Mathis formula
Optimization
Control theory
Nonlinear model
Stocahstic model
abstraction
live netwk WANinLab emulation
simulation
maths
All scales are important– WAN-in-Lab fills a gap
Wind Tunnel of Networking
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WAN in Lab
• Capacity: 2.5 – 10 Gbps
• Delay: 0 – 120 ms round trip
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Configurable & evolvable
• Topology, rate, delays, route
• Modular design stays up to date
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Breakable
• Won’t take down real network
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Flexible, active debugging
• Passive monitoring, AQM
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Integral part of R&A networks
• Transition from theory, implementation, demonstration,
deployment
• Transition from lab to marketplace
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Global resource
• Part of global infrastructure UltraLight led by Harvey Newman
Projects
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TCP benchmarking
FAST
• Delay-based congestion control
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MaxNet
• Explicit signalling congestion control
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MojaveFS
• New distributed file system
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University of Pittsburg
• TCP with small buffers
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University of Melbourne
• Single-bit congestion marking
Example project: MaxNet
Hardware Router
Hardware Router Hardware Router
Hardware Router
14 ms delay
14 ms delay
8x400km OC-48 2.5Gbps
8x400km OC-48 2.5Gbps
1 Gbit/sec
1 Gbit/sec
Bottleneck
Router 1
Bottleneck
Router 2
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Host A
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Host B
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Host C
Listening
server
Sample MaxNet results
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Achieves realistic delay at 1Gbit/s
Equipment
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4 Cisco 7609 routers with OC48 line cards
6 Cisco ONS 15454 switches
A few dozen high speed servers
1G switch to routers/servers
Calient switch for OC48
2,400 kilometres of fibre, optical
amplifiers, dispersion compensation
modules
63ms aggregate RTT delay, in two hops
• 120ms using IP loopbacks
External connections
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Will link to Ultralight, 10Gbps Physics WAN
Smooth migration testing -> deployment
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Delay
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• longer
• jitter
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Cross traffic
Monitor
data routed
through WiL
Configuration -- Delays
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Want maximum delay from limited fibre
• Signals traverse fibre 16 times
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4 WDM wavelengths
4 OC48 (2.5G) MUXed onto OC192 (10G)
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Lots of transponders
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• WDM amplifier joins 100km spools  200km
Configuration – delays
OC48 slot
16x200km
-------WDM Wavelength--------
Bidirectional 100km
Bidirectional 100km
Amp
Configuration – delays
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Delay varied by adjusting the number of
OC48 hops traversed
Calient optical switch selects required
hops
Hop lengths 200km up to 1600km
• Maximise granularity given limited switch ports
Switch
Future plans
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Better control over capacities and buffers
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Saturating links
• Current servers 1Gbps, links 2.5Gbps
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Creative ways to emulate more topologies
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Investigate cross-traffic generation
• Harpoon currently installed
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Better monitoring
Using WAN-in-Lab
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Contact me – lachlan at caltech . Edu
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Coarse timesharing
• Some users set up experiments while others
run experiments
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Software setup still being developed
• Your chance to influence our directions to tailor
it to your needs
Conclusion
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WAN-in-Lab fills the gap between
emulation and live network experiments
Seeks to be as realistic as possible
• Long links, simple topology
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Focus will be on TCP benchmarking
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We encourage people to use it