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


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 ([email protected]) 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 secondshttp://www.psc.edu/~mathis/papers/JTechs200105/

GigE/655: 10-8, 1 loss every 497 seconds


Enabling Divide & Conquerand Ongoing Monitoring

Backbone 1GigaPoP A

Campus

CampusGigaPoP B

Backbone 2

Wall Jack

Wall Jack

P

P


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, [email protected]

Measurements Working Group•http://www.internet2.edu/measurement/

End-to-end interest list• [email protected]•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/

www.internet2.edu

30 may 2001 campus measurement matt zekauskas, [email protected] internet2 campus workshop atlanta,...

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