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Campus Measurement. Matt Zekauskas, matt@internet2.edu Internet2 Campus Workshop Atlanta, GA. Outline. Existing measurement tools & projects A sample performance problem Vision for infrastructure to solve problems Steps campuses can take today. My Bias.
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Campus Measurement Matt Zekauskas, matt@internet2.edu Internet2 Campus Workshop Atlanta, GA
Outline • Existing measurement tools & projects • A sample performance problem • Vision for infrastructure to solve problems • Steps campuses can take today
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)
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!
Measurement Goals • Solving performance problems • Network operations • Network engineering • Network research • Operational data • performance, flows, anomalies • Network characterization • how used? load response? SLS?
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
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
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?
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
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)
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
AMP • Like Surveyor, but • Round-trip latency instead of one-way • Easier to deploy • Working on more comprehensive set of “alarms” • Potentially more available
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
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.
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
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 (matt@internet2.edu) if you want to perform an ad-hoc test
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/
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
Others via Abilene NOC • BGP Peering • MSDP (multicast source discovery) logging • See: http://www.abilene.iu.edu/-> Operational Status
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/
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!
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
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)
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 seconds • http://www.psc.edu/~mathis/papers/JTechs200105/ • GigE/655: 10-8, 1 loss every 497 seconds
Campus Backbone 1 Backbone 2 Campus GigaPoP A GigaPoP B Enabling Divide & Conquerand Ongoing Monitoring Wall Jack P P Wall Jack
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’)
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
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
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/
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
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
NTP everywhere! • If GPS, get good NTP distribution • Allow correlation among campuses
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
Contact Information • Matt Zekauskas, matt@internet2.edu • Measurements Working Group • http://www.internet2.edu/measurement/ • End-to-end interest list • listserv@internet2.edu • subscribe e2e-interest
(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/