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Transcript of 30 May 2001 Campus Measurement Matt Zekauskas, [email protected] Internet2 Campus Workshop Atlanta,...
30 May 2001
Campus Measurement
Matt Zekauskas, [email protected]
Internet2 Campus Workshop
Atlanta, GA
30-May-2001 2Campus Measurement
Outline
Existing measurement tools & projects
A sample performance problem
Vision for infrastructure to solve problems
Steps campuses can take today
30-May-2001 3Campus Measurement
My Bias
I once ran a (corporate) campus network
My recent focus: measurements
Most recently: end-to-end performance
I have been helping solve some wide-area performance problems
Caveat: I haven’t been doing the fixing (My view is from the center)
30-May-2001 4Campus Measurement
We Need Your Help
I have probably missed something
Give us the benefit of your experience • fixing problems•operating a network
…also join a working group!
30-May-2001 5Campus Measurement
Measurement Goals
Solving performance problems
Network operations
Network engineering
Network research
Operational data• performance, flows, anomalies
Network characterization• how used? load response? SLS?
30-May-2001 6Campus Measurement
Measurements from the Center
Active•Measurement within Abilene•Measurement using entire Internet2 infra.
Passive•SNMP stats (esp. core Abilene links)• “IOS” stats (for QoS)•Characterization of traffic (on the way)
–Netflow; OCxMON
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Measurement Projects
Surveyor (one-way delay, loss, routing)• www.advanced.org/surveyor • On many Internet2 campuses (70 sites)• Abilene presence
AMP (round-trip delay, loss, routing)• moat.nlanr.net/AMP• At even more Internet2 campuses (120 sites)
PMA (passive, packet traces)• moat.nlanr.net/PMA• 1 min, 8 times a day, ~13 sites
30-May-2001 8Campus Measurement
Measurement Projects
PingER (round-trip delay, routing)• http://www-iepm.slac.stanford.edu/pinger/• Long term data from a few locations to many• High-energy physics focus
NIMI• http://www.ncne.nlanr.net/nimi/• Designed to be platform for experiments• Undergoing some redesign/revitalization• ~ 60 sites?
30-May-2001 9Campus Measurement
Usefulness
AMP, Surveyor, Pinger• If at your campus, a view from your campus• If at destination, a view of destination• Look for campus connected to same gigaPoP if not at local or destination
• [“Phase 0” measurement points for e2eperf]
• Routing, congestion problems
30-May-2001 10Campus Measurement
Usefulness
PMA• If at your campus, can look at traces for anomalies
•Not as useful for on-demand debugging(but don’t ignore ability to take traces)
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Surveyor on One Slide
Continuous measurement
One-way delay and loss
1/sec on Poisson Schedule
12 Byte UDP packets
Traceroutes at 1/600 sec
72 Machines• http://hartman.advanced.org/IPPMApplet/report/Report.html -- Java, close to real-time
• http://ippm-db.advanced.org/plots/ -- static
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AMP
Like Surveyor, but•Round-trip latency instead of one-way
–Easier to deploy
•Working on more comprehensive set of “alarms”
•Potentially more available
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An “Application-Level” Example
Pioneer•http://pelle.internet2.edu:8080/pioneer/•Synthesis of existing infrastructure•Focus: video conferencing tests
•Goal: use this to tell if video likely to work
30-May-2001 17Campus Measurement
Abilene
Abilene goal to be an exemplar•Measurements open•Tests possible to router nodes•Web-mediated on-demand measurements•Throughput tests routinely through backbone
•…as well as existing utilization, etc.
30-May-2001 18Campus Measurement
Active within Abilene
Each Router Node has a PC
Now 10 of 11 are OC3-ATM attached•missing: Houston
No GPS•working towards GPS within CDMA solution
30-May-2001 19Campus Measurement
Ad-hoc Active on Abilene
With OC-3, can do moderate throughput testing (e.g., iperf UDP & TCP). ~90 Mbps
Adding on-demand tests in support of performance debugging
Contact me ([email protected]) if you want to perform an ad-hoc test
30-May-2001 20Campus Measurement
Passive - Utilization
The Abilene NOC takes•Packets in,out•Bytes in,out•Drops/Errors• ..for all interfaces, publishes internal links & peering points (at 5 min intervals)
• ..via SNMP polling – every 3 sec
http://hydra.uits.iu.edu/~abilene/traffic/
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Passive – Characterization
Some sparse via NLANR/MOAT•http://moat.nlanr.net/PMA/
Starting some NetFlow measurements•QoS•AS-AS information for K-20 & ITN• Intend to do some characterization
30-May-2001 24Campus Measurement
Others via Abilene NOC
BGP Peering
MSDP (multicast source discovery) logging
See: http://www.abilene.iu.edu/-> Operational Status
30-May-2001 25Campus Measurement
Multicast-specific
Multicast measurements•Not fully understood•Debugging is an art
Tools•Mtrace• ‘sdr’ announcements in backbone•Mhealth, Mantra via UCSBhttp://www.nmsl.cs.ucsb.edu/ http://www.cs.ucsb.edu/~almeroth/
30-May-2001 26Campus Measurement
JPL/Caltech – GSFC
The situation•Using Abilene•Tuned hosts•Things work locally
Therefore it MUST be Abilene•Tests show good flows router-router• Intermediate tests point towards CA
Bad fiber connection!
30-May-2001 27Campus Measurement
Vision I
Ongoing monitoring to test major elements, and (some, important) end-to-end paths.
•Elements: gigaPoP links, peering, …•Utilization •Delay•Loss•Occasional throughput•Multicast connectivity
30-May-2001 28Campus Measurement
Vision II
There are many more paths end to end than can be monitored.
Diagnostic tools available on-demand (with authorization)
•Show routes•Perform flow tests (perhaps app tests)•Parse/debug flows (a-la tcpdump or OCXmon with heuristic tools)
30-May-2001 29Campus Measurement
For TCP (and Streaming)
Eliminating loss is the goal
Focus on noncongestive losses
TCP: 100 Mbit Ethernet coast-to-coast:•Full size packets… need 10-6 Ploss [Mathis]
•Less than 1 loss every 83 secondshttp://www.psc.edu/~mathis/papers/JTechs200105/
GigE/655: 10-8, 1 loss every 497 seconds
30-May-2001 30Campus Measurement
Enabling Divide & Conquerand Ongoing Monitoring
Backbone 1GigaPoP A
Campus
CampusGigaPoP B
Backbone 2
Wall Jack
Wall Jack
P
P
30-May-2001 31Campus Measurement
Some Commercial Tools
Caveat: only a partial list, give me more!
Spirent (nee Netcom/Adtech): • working on a box for ‘end-to-end’ measurements• SmartBits: test at low & high rates, QoS; test components or end-to-end path
NetIQ: Chariot/Pegasus
Ixia (like SmartBits/Spirent); Agilent
Brix Networks (like Surveyor, for ‘QoS’)
30-May-2001 32Campus Measurement
Some Noncommercial Tools
Iperf: dast.nlanr.net/Projects/iperf• See also http://www-itg.lbl.gov/nettest/
Flowscan: • http://www.caida.org/tools/utilities/flowscan/ • http://net.doit.wisc.edu/~plonka/FlowScan/
SLAC’s traceroute perl script:• http://www.slac.stanford.edu/comp/net/wan-mon/traceroute-srv.html
One large list: • http://www.slac.stanford.edu/xorg/nmtf/nmtf-tools.html
30-May-2001 33Campus Measurement
What You Can Do
Export SNMP data• I can keep an “internet2 list”, would like it to be public [Current Measurement WG project]
• Monitor loss as well as throughput
Performance test point at campus edge• Netperf or iperf, so can be from anywhere• Traceroute “looking glass”• Commercial (e.g., NetIQ) complements• I’m willing to keep a master list [MWG project]
Portable performance test point
30-May-2001 34Campus Measurement
For TCP Tuning
Keep an eye out for Web100:•http://www.web100.org/
NCNE Tuning Page:• http://www.psc.edu/networking/perf_tune.html •http://www.ncne.nlanr.net/research/tcp/
30-May-2001 35Campus Measurement
What You Can Do
If you have a Cisco router at your edge, use NetFlow and cflowd + FlowScan to see your traffic characteristics
RTFM / RMON probes
See also Joe St.Sauver’s presentation from the last “Joint Techs” meeting:http://www.ncne.nlanr.net/training/techs/2001/0514/
presentations/200105-sauver1.html
30-May-2001 36Campus Measurement
A Summer Project
Measurement box at edge
Spend month or two with mobile box, checking throughput/loss/.. from every point.
Eliminate noncongestive losses
Develop a baseline to get a complete picture of the campus: map the campus networks
30-May-2001 37Campus Measurement
NTP everywhere!
If GPS, get good NTP distribution
Allow correlation among campuses
30-May-2001 38Campus Measurement
Plug: Internet2 Measurement Working Group Activities
Measurement architecture
Encourage common•Measurements, tools•Parameters•Reporting
Work with (at least) management, QoS, multicast; End-to-end Performance Initiative
30-May-2001 39Campus Measurement
Contact Information
Matt Zekauskas, [email protected]
Measurements Working Group•http://www.internet2.edu/measurement/
End-to-end interest list• [email protected]•subscribe e2e-interest
30-May-2001 40Campus Measurement
(Some) URLs
Http://www.internet2.edu/measurement/
http://www.advanced.org/surveyor/
http://moat.nlanr.net/ http://dast.nlanr.net/
http://www.ncne.nlanr.net/ http://www.ncne.org/
http://www.caida.org/ http://www.web100.org/
http://www.auckland.ac.nz/net/Internet/rtfm/http://www.slac.stanford.edu/xorg/icfa/ntf/home.html
http://www.merit.edu/ipma/
www.internet2.edu