Measuring the Digital Divide with PingER

Prepared by Les Cottrell, SLAC, for the Round Table: Developing Countries Access to Scientific

Knowledge, October 23-24, 2003, ICTP Trieste, Italy

www.slac.stanford.edu/grp/scs/net/talk03/ictp-oct03.ppt

Partially funded by DOE/MICS Field Work Proposal on Internet End-to-end Performance Monitoring (IEPM), also

supported by IUPAP

Methodology

• Use ubiquitous ping

• Each 30 minutes from monitoring site to target : – 1 ping to prime caches– by default send10x100Byte pkts– 10x1000Byte pkts

• Record loss & RTT, (+ reorders, duplicates)

• Derive throughput, jitter, unreachability …

Architecture

• Hierarchical vs. full mesh

WWWWWW

ArchiveArchive

MonitoringMonitoringMonitoringMonitoring MonitoringMonitoring

RemoteRemote

RemoteRemoteRemoteRemote

RemoteRemote

FNAL

Reports & Data

CacheMonitoringMonitoring

SLAC Ping

HTTP

ArchiveArchive

1 monitor hostremote host pair

Countries Monitored

Recent additions• Added hosts in Macedonia, Serbia/Montenegro,

Belarus, Turkey, Armenia, Mexico and Azerbaijan, Tajikistan, Turkeministan, Kyrgyzstan

• Contacts– Working with contacts in Vietnam, the Philippines, Albania,

and Tunisia – Looking for contacts in Cuba, Kenya, Algeria and South

Africa, Uganda– Working with Iran site to set up monitor host

• Increased hosts monitored from CERN to give better European view – Now monitoring 60 countries

Countries Monitored

Used to monitorOnly 1 host

Need > 1 host to reduce anomalies

Country

Hosts Country

Hosts Country

Hosts Country Hosts

Albania 0 Estonia 1 Latvia 1 Slovakia 2

Argentina 6 Finland 1 Lithuania 1 Slovenia 1

Armenia 2 France 11 Macedonia 2 S Africa 3

Australia 4 Georgia 2 Malaysia 3 Spain 6

Austria 2 Germany 13 Mexico 5 Sweden 4

Azerbaijan 2 Ghana 1 Moldova 2 Switzerland 8

Bangladesh 1 Greece 1 Mongolia 1 Taiwan 1

Belarus 2 Guatemala 2 Netherlands 12 Tajikstan 1

Belgium 3 Hungary 5 New-Zealand 4 Thailand 1

Brazil 21 Iceland 3 Nigeria 1 Turkey 2

Bulgaria 1 India 10 Norway 2 Turkmenistan 1

Canada 11 Indonesia 3 Pakistan 1 Uganda 1

Chile 4 Iran 4 Peru 1 Ukraine 2

China 6 Ireland 2 Phillippines 0 UK 36

Colombia 4 Israel 5 Poland 4 US 208

Costa-Rica 1 Italy 13 Portugal 2 Uruguay 3

Croatia 5 Japan 11 Romania 1 Uzbekistan 2

Cuba 2 Jordan 1 Russia 12 Venezuela 2

Czech-Rep 3 Kazakhstan 2 Saudi Arabia 1 Vietnam 0

Denmark 1 Korea 2Serbia & Montenegro 2  

Egypt 1 Kyrghzstan 1 Singapore 1  

~ 80 countries

480 sites

800 hosts

3600 pairs

PingER Benefits

• Provides quantitative historical (> 8yrs) and near real-time information– Aggregate by regions, affiliations etc.– How bad is performance to various

regions, rank countries?– Trends: who is catching up, falling behind,

is progress being made?– Compare vs. economic, development

indicators etc.• Use for trouble shooting setting

expectations, identify needed upgrades, choosing a provider, presenting to policy makers, funding bodies

Monitoring site vs. Remote sites screen shot

• Aimed at: end-user (net-admin & sophisticated user), planners • Measures analyzes & reports round-trip times, losses, availability,

throughput ...– Uses ubiquitous ping, no special host, or software to install/configure at remote

sites– Low impact on network << 100bits/s, important for many DD sites– Covers 75+ countries (99% of Internet connected population)

Usage Examples

Median Packet Loss Seen From nbi.dk

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Smurf Filtersmurf Filtersinstalled oninstalled onNORDUnet’sNORDUnet’sUS connection.US connection.

To North America

To Western Europe

Packet Loss between DESY and FNAL in February and March 2000.

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DFN closes Perryman POP and looses direct peering with ESnet

Peering re-established via Dante at 60 Hudson

February March

Peering problems

Upgrades & ping filtering

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

E.g. PartialRate Limiting

RTT Loss

2 hosts at same site see sudden step-like increase in loss from < 1% to 20-30% at similar time

boromir.nask.waw.pl

gollum.nask.pl

www.pol34.plAnother host in Poland sees no problems, i.e. helps to have another nearby host

RT

T Los

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Similar effects for Greek (uoa.gr), Bulgarian (acad.bg), Kazakhstan (president.kz), Moldovan (asm.md) and Turkish (metud.edu.tr) sites

If no step function or nearby host may not notice, so also compare synack vs ping

At any given time, about 5% of monitored hosts are doing this, most in developing countries. Recently (August 2003) seen an increase in ping rate limiting

Digital Divide Regions• Design regions

– to match well known world regions and – to have similar connectivity within region

• Then order by derived throughput– Derived throughput ~ MSS/(RTT*sqrt(loss))

• Want to show general behavior & variability (outliers)• Developed:

– U. S.+Canada, Japan+Taiwan+Singapore+Korea, Australia+NZ, Europe (excl. SE Europe, Russia)

• Developing (Digital Divide):– Africa, S. America, C. America, C. Asia, China, S. Asia, Caucasus, M.

East, SE Europe, Russia

Israel has much better connectivity than neighbors in Mid East so distorts Mid East results, move to Europe?!Greece is part of Europe, should it be part of S. E. Europe, choice varies with time…

Region Map

• Also have affinity groups, e.g. AMPATH, Silk Road, CMS, XIWT and can select multiple groups

Current State – Aug ‘03 (throughput)

• 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/sGood > 1000kbits/s

Trends

Africa shown for onlyUganda seen from SLAC,since adding new countries with very different throughputs distorts result

S.E. Europe, Russia: catching upLatin Am., Mid East, China: keeping upIndia, Africa: falling behind

Derived throughput~MSS/(RTT*sqrt(loss))

Russia

• 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

Loss Comparisons with Development (UNDP)

Even weaker with education & literacy

Weak correlation with Human Development or GDP

Human Development Index (HDI ) RankSource: UN

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NREN Core Network Size (Mbps-km)

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Leading

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In transition

Source: From slide prepared by Harvey Newman, presented by David Source: From slide prepared by Harvey Newman, presented by David Williams ICFA/SCIC talk on Serenate report. Data from the TERENA Williams ICFA/SCIC talk on Serenate report. Data from the TERENA CompendiumCompendium

Lagging

Derived throughput~MSS/(RTT*sqrt(loss))

Europe

Netherlands

Turkey

Belgium

Network Readiness

• NRI from Center for International Development, Harvard U. http://www.cid.harvard.edu/cr/pdf/gitrr2002_ch02.pdf

• Using derived throughput ~ MSS / (RTT * sqrt(loss))– Fit to exponential is better

Internet for all focusA

&R

focus

NRI Top 14Finland 5.92US 5.79Singapore 5.74Sweden 5.58Iceland 5.51Canada 5.44UK 5.35Denmark 5.33Taiwan 5.31Germany 5.29Netherlands 5.28Israel 5.22Switzerland 5.18Korea 5.10

Challenges• 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• have played with automating alerts, data will/is available via web services

• 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

• Derived throughputs poor for well connected sites (<0.1% loss)• Funding

– “Unfortunately, network management research has historically been very under-funded, because it is difficult to get funding bodies to recognize this as legitimate networking research.” Sally Floyd, IAB Concerns & Recommendations Regarding Internet Research & Evolution.

– http://www.ietf.org/internet-drafts/draft-iab-research-funding-00.txt

• 35+ monitoring sites in 15 countries– Plan to add ICTP Trieste if funded – Other projects used toolkit, e.g. XIWT, PPCNG/EDG …

• SLAC with help from FNAL• Digital Divide collaboration (MOU) with ICTP, Trieste

– eJDS– They are looking for a EU grant for eJDS and PingER

• Need funding for coming year:– Working with DoE, NSF, Pew Charitable Foundation …– Tasks:

• (0.5 FTE) ongoing maintain data collection, explain needs, reopen connections, open firewall blocks, find replacement hosts, make limited special analyses, prepare & make presentations, respond to questions

• (+ 0.5 FTE) extend the code for new environment (more countries, more data collections), fix known non-critical bugs, improve visualization, automate some of reports generated by hand today, find new country site contacts, add route histories and visualization, automate alarms, detect rate limiting earlier, update web site for better navigation, add more DD monitoring sites/countries, improve code portability, understand regions better

• Also looking for small grants for helpers in developing countries• ICFA: show importance to policy makers, funding agencies, identify

sympathetic contacts at agencies, get support• Ported to IPv6

Collaborations & Funding

Futures• More work on understanding regions

• Better/quicker detection of rate limiting

Summary• Valuable light-weight tool for end-to-end performance• Good for trouble-shooting, planning, setting

expectations• World wide coverage• Performance from U.S. is improving all over• Performance to developed countries are orders of

magnitude better than to developing countries• Poorer regions 5-10 years behind• Poorest regions Africa, Caucasus, Central & S. Asia• Some regions are:

– catching up (SE Europe, Russia), – keeping up (Latin America, Mid East, China), – falling further behind (e.g. India, Africa)

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

Extra Slides

VisualizationKeep it simple, enable user to do their

own by making data available • Tables

– Time series (www-iepm.slac.stanford.edu/cgi-

wrap/pingtable.pl): • select metric (loss, RTT etc.), time ticks,

packet size, aggregations from/to, etc.

• Color code numbers, provide sort, drill down to graphs, download data (TSV), statistical summaries

– Monitoring site vs. Remote sites (www-

iepm.slac.stanford.edu/cgi-wrap/table.pl):• Select metric, region aggregations

• Drill down to time series, download data

• Graphs– Select source(s)/destination(s), metric,

time window, SQL selects, graph type

Publish information

#!/usr/bin/perl use SOAP::Lite; my $characteristic = SOAP::Lite -> service(‘http://www-iepm.slac.stanford.edu/tools/soap/wsdl/profile_06.wsdl') -> pathDelayOneWay("tt81.ripe.net:tt28.ripe.net”); print $characteristic->{NetworkTestTool}->{toolName},"\n"; print $characteristic->{NetworkPathDelayStatistics}->{value},"\n";

• www.slac.stanford.edu/cgi-wrap/pingtable.pl => tabular reports, also download data

• Data accessible from MonaLisa• Implementing web services

access prototype– Includes: PingER, IEPM-BE, RIPE-tt,

I2 E2Epi OWAMP– Use GGF/NMWG schema/profile,

e.g.• path.delay.roundTrip

Rate Limiting Moldova

cni.md

lises.asm.md

RTT Loss

Moldova Bulgaria