1 PingER: Methodology, Uses & Results Les Cottrell SLAC, Warren Matthews GATech Extending the Reach of Advanced Networking: Special International Workshop Arlington, VA., April 22, Partially funded by DOE/MICS Field Work Proposal on Internet End-to-end Performance Monitoring (IEPM), also supported by IUPAP

2 Outline What is PingER World Internet performance trends Regions and Digital Divide Examples of use Challenges Summary of Uses

3 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 …

4 Architecture Hierarchical vs. full mesh WWW Archive Monitoring Remote FNAL Reports & Data Cache Monitoring SLAC Ping HTTP Archive 1 monitor host remote host pair ~35 ~550

5 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

6 World Trends Increase in sites with Good (<1%) loss 25% increase in sites monitored –Big focus on Africa 4=>19 countries –Silk Road

7 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 AMPath NaukaNet/ Gloriad

8 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 Bad < 200kbits/s < DSL Poor > 200, < 500kbits/s Acceptable > 500kbits/s, < 1000kbits/s Good > 1000kbits/s

9 Examples of Use Need for constant upgrades Upgrades Filtering Pakistan

10 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

11 Russia Examples E.g. Upgrade to KEK-BINP link from 128kbps to 512kbps, May ’02: improved from few % loss to ~0.1% loss Russian losses improved by factor 5 in last 2 years, due to multiple upgrades

12 Usage Examples Ten-155 became operational on December 11. murf Filters Smurf Filters installed on NORDUnet’s US connection. To North America To Western Europe Peering problems, took long time identify/fix Upgrades & ping filtering

13 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

14 Challenges 1 of 2 Ping blocking –Complete block easy to ID, then contact site to try and by- pass, can be frustrating for 3 rd 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

15 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

16 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

17 More Information PingER: –www-iepm.slac.stanford.edu/pinger/www-iepm.slac.stanford.edu/pinger/ MonaLisa –monalisa.cacr.caltech.edu/monalisa.cacr.caltech.edu/ GGF/NMWG –www-didc.lbl.gov/NMWG/www-didc.lbl.gov/NMWG/ ICFA/SCIC Network Monitoring report, Jan03 – Monitoring the Digital Divide, CHEP03 paper –arxiv.org/ftp/physics/papers/0305/ pdfarxiv.org/ftp/physics/papers/0305/ pdf Human Development Index – Network Readiness Index –