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PingER: Methodology, Uses & Results. Les Cottrell SLAC, Warren Matthews GATech Extending the Reach of Advanced Networking: Special International Workshop Arlington, VA., April 22, 2004 www.slac.stanford.edu/grp/scs/net/talk03/i2-method-apr04.ppt.
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PingER: Methodology, Uses & Results Les Cottrell SLAC, Warren Matthews GATech Extending the Reach of Advanced Networking: Special International Workshop Arlington, VA., April 22, 2004 www.slac.stanford.edu/grp/scs/net/talk03/i2-method-apr04.ppt Partially funded by DOE/MICS Field Work Proposal on Internet End-to-end Performance Monitoring (IEPM), also supported by IUPAP
Outline • What is PingER • World Internet performance trends • Regions and Digital Divide • Examples of use • Challenges • Summary of Uses
Methodology • Use ubiquitous ping • Each 30 minutes from monitoring site to target : • 1 ping to prime caches • by default send11x100Byte pkts followed by 10x1000Byte pkts • Low network impact + no software to install / configure / maintain at remote sites + no passwords / accounts needed = good for developing sites / regions • Record loss & RTT, (+ reorders, duplicates) • Derive throughput, jitter, unreachability …
Architecture • Hierarchical vs. full mesh WWW HTTP Ping SLAC Reports & Data Archive FNAL Archive ~35 Monitoring Monitoring Monitoring Cache Monitoring Remote 1 monitor host remote host pair Remote Remote Remote ~550
Regions Monitored • Recent added NIIT PK as monitoring site • White = no host monitored in country • Colors indicate regions • Also have affinity groups (VOs), e.g. AMPATH, Silk Road, CMS, XIWT and can select multiple groups Monitoring sites in ~ 35 countries
World Trends • Increase in sites with Good (<1%) loss • 25% increase in sites monitored • Big focus on Africa 4=>19 countries • Silk Road
Trends S.E. Europe, Russia: catching up Latin Am., Mid East, China: keeping up India, Africa: falling behind Derived throughput~MSS/(RTT*sqrt(loss)) Silk Road NaukaNet/ Gloriad AMPath
Current State – Aug ‘03 thruput ~ MSS / (RTT * sqrt(loss)) • Within region performance better • E.g. Ca|EDU|GOV-NA, Hu-SE Eu, Eu-Eu, Jp-E Asia, Au-Au, Ru-Ru|Baltics • Africa, Caucasus, Central & S. Asia all bad Acceptable > 500kbits/s, < 1000kbits/s Bad < 200kbits/s < DSL Poor > 200, < 500kbits/s Good > 1000kbits/s
Examples of Use • Need for constant upgrades • Upgrades • Filtering • Pakistan
Usage Examples • Selecting ISPs for DSL/Cable services for home users • Monitor accessibility of routers etc. from site • Long term and changes • Trouble shooting • Identifying problem reported is probably network related • Identify when it started and if still happening or fixed • Look for patterns: • Step functions • Periodic behavior, e.g. due to congestion • Multiple sites with simultaneous problems, e.g. common problem link/router … • Provide quantitative information to ISPs Identify need to upgrade and effects • BW increase by factor 300 • Multiple sites track • Xmas & summer holiday
Russia Examples • Russian losses improved by factor 5 in last 2 years, due to multiple upgrades • E.g. Upgrade to KEK-BINP link from 128kbps to 512kbps, May ’02: improved from few % loss to ~0.1% loss
Usage Examples To North America Ten-155 became operational on December 11. Smurf Filters installed on NORDUnet’s US connection. Upgrades & ping filtering To Western Europe Peering problems, took long time identify/fix
Pakistan Example • Big performance differences to sites, depend on ISP (at least 3 ISPs seen for Pakistan A&R sites) • To NIIT (Rawalpindi): • Get about 300Kbps, possibly 380Kbps at best • Verified bottleneck appeared to be in Pakistan • There is often congestion (packet loss & extended RTTs) during busy periods each weekday • Video will probably be sensitive to packet loss, so it may depend on the time of day • H.323 (typically needs 384Kbps + 64Kbps), would appear to be marginal at best at any time. • Requested upgrade to 1Mbps, and verified got it (Feb ’04) • No peering Pakistan between NIIT and NSC
Challenges 1 of 2 • Ping blocking • Complete block easy to ID, then contact site to try and by-pass, can be frustrating for 3rd world • Partial blocks trickier, compare with synack • Effort: • Negligible for remote hosts • Monitoring host: < 1 day to install and configure, occasional updates to remote host tables and problem response • Archive host: 20% FTE, code stable, could do with upgrade, contact monitoring sites whose data is inaccessible • Analysis: your decision, usually for long term details download & use Excel • Trouble-shooting: • usually re-active, user reports, then look at PingER data • Working on automating alerts, data is available for download
Challenges 2 of 2 • Funding • DoE development/research funding ended 2003 • Looking for alternate funding sources • Sustain, maintain & extend databases & measurements to more countries • Get measurements FROM & within developing regions • New analyses, preparing & presenting reports • Making contacts, coordinating efforts
Uses • Near real time results: • Trouble shooting, detect problems see when they occur • Long term trends: • Set expectations, planning, • Give sites/regions better idea of how good/bad things are • Input to policy and funding agencies, assist in deciding where help is needed and how to provide • Measure before & after upgrades • Is it working right, did we get our money’s worth
More Information • PingER: • www-iepm.slac.stanford.edu/pinger/ • MonaLisa • monalisa.cacr.caltech.edu/ • GGF/NMWG • www-didc.lbl.gov/NMWG/ • ICFA/SCIC Network Monitoring report, Jan03 • www.slac.stanford.edu/xorg/icfa/icfa-net-paper-dec02 • Monitoring the Digital Divide, CHEP03 paper • arxiv.org/ftp/physics/papers/0305/0305016.pdf • Human Development Index • www.undp.org/hdr2003/pdf/hdr03_backmatter_2.pdf • Network Readiness Index • www.weforum.org/site/homepublic.nsf/Content/Initiatives+subhome