PingER : Actively measuring the worldwide Internet’s end-to-end performance

PingER: Actively measuring the worldwide Internet’s end-to-end performance

Les CottrellSLAC

MYREN meeting, Kuala Lumpur

December 12, 2012

AgendaUsing PingER measurements going back to 1998 and covering 168 countries, this talk will illustrate, Internet performance worldwide.

•Brief history

•How can the Internet help development?

•How does PingER measure Internet performance?

•What do we measure, what does it tell us?

•What do we find?

•Case studies illustrating PingER

History• Story of Ping

• Early PingER

• Extension to Developing Regions

• Extension to Pakistan

• Extension to Malaysia

The start• Ping tool invented by Mike Muus

– “a little thousand-line hack” during a single evening to troubleshoot “odd behavior” on the computer network at the U.S. Army’s Ballistic Research Laboratory in Maryland.

– sent a small data packet known as an echo request to an IP address, typically a remote server or network node. If the target address was reachable, it echoed back the same data, and the program recorded the time it took for the round-trip journey.

– Reminded Muuss of the percussive sound pulse sonar systems use to detect objects underwater, he named it after that sound—ping.

5 Joint Techs: I2 & ESnet,Stanford

Measurement Mechanism: PingER

Internet

10 ping request packets each 30 mins

RemoteHost(typicallyweb server)

>ping remhost

Ping response packets

Measure Round Trip Time & Loss

Monitor Host

6

Early PingER• As the head of networking at SLAC, I set up the

system using ping simply to test connections between the laboratory and several dozen research institutions in about a dozen countries that were collaborating on a physics experiment known as BaBar to study properties of subatomic particles.

• Over the next half-decade, as word of PingER’s value spread, I extended monitoring to hundreds more physics laboratories and science centers across the globe. But the project didn’t take a humanitarian turn until 2001.

•UNIMAS

Workshop, Sarawak, Dec 2012

7

Extension to the Developing regions• In 2001 I visited ICTP in Italy.• Driven by ICTP’s goals of bringing first-class science

and technology to developing countries they wanted to know how well the networks were working.

• The simple PingER project was the perfect tool for the job. Ubiquitous ping so nothing to install at remote targets.

• They offered to help expand the project to those parts of the world that needed it most.

• Within the next year, we began establishing monitoring and target hosts in countries as diverse as Ecuador, Rwanda, Jordan, and Bhutan.

UNIMASWorkshop, Sarawak, Dec 2012

8

Extension to Pakistan• In 2004 set up joint agreement with NUST in Pakistan• Soon got my first real glimpse of just how much of a

difference PingER can make. – Set up a PingER monitoring site in the country to

assess performance on the then year-old Pakistan Educational Research Network (PERN).

– The network’s providers touted its bandwidth of 155 Mbps, impressive at the time. But PingER revealed that the “last mile” links to universities were dreadful. These bottleneck connections funneled data at no more than 1 Mbps, causing long delays and high packet loss.


9

Extension to Pakistan

• He clearly took PingER’s lessons to heart. When construction of PERN2 began in 2009, its plans included extending high-speed, 1-Gbps data links all the way to university data centers


• During a visit to the university, I presented our findings to the chairman of Pakistan’s higher education commission, Atta-ur-Rehman, who was preparing to fund the next major upgrade to PERN.

10

Extension to Malaysia

• Have set up an official signed MoU between SLAC & U of Malaysia in Sarawak (UNIMAS)

• Idea was to replicate the NUST project

• Fortnightly meetings by Skype

• Just getting started, no students yet

• Met with Vice Chancellor (VC) at one meeting

• This workshop is a follow up.


11

Why do measurements of the Internet matter


Why does it matter

• African scientists isolated

• Lack critical mass

• Need network to collaborate but it is terrible

• Brain drain

• Brain gain, tap diaspora

• Blend in distance learning

• Provide leadership, train trainers

12

Internet Users 2002

Cartograms from:www.geog.qmw.ac.uk/gbhgis/conference/cartogram.html

Tertiary Education fromhttp://www.worldmapper.org/

http://www.geog.qmw.ac.uk/gbhgis/conference/cartogram.html

http://www.geog.qmw.ac.uk/gbhgis/conference/cartogram.html

13 eGY Africa 2012Workshop, Nairobi Oct 2012

How does the Internet help• Investment in information technology plays the role of

a "facilitator" that allows other innovations to take place. http://findarticles.com/p/articles/mi_m1093/is_3_45/ai_86517828/

• World Bank / IFC report: for every 10% increase in high-speed Internet connections there is an increase in economic growth of 1.3 percentage points. April 2010. http://www.infodev.org/en/Article.522.html

• Example: Uganda 15% increase in price of maize based on improved farmer bargaining power. www.itu.int/ITU-D/.../S1-01-NG-ICT_Indicators-Tim_Kelly.pptx

14

How does PingER work

• Mechanism

• Coverage


15 Joint Techs: I2 & ESnet,Stanford

Measurement Mechanism: PingER

Internet

10 ping request packets each 30 mins

RemoteHost(typicallyweb server)

>ping remhost

Ping response packets

Measure Round Trip Time & Loss

On

ce a Day

Uses ubiquitous ping

Monitor Host

Repositories

NUST

16

Deployment• Monitors > 90 in 23 countries, 4 in Africa

Summer Joint TechsStanford, July 2012

• Beacons monitored by most monitors (~100)• Remote sites monitored by some monitors (~750)

17

Metrics Available from PingER• UnReachability

• Minimum RTT

• Average RTT

• Jitter

• Loss

• Derived throughput

• MOS

• Directness of Connection

• OthersUNIMAS

Workshop, Sarawak, Dec 2012

18 eGY Africa 2012Workshop, Nairobi Oct 2012

Unreachability


Unreachability: e.g. N. African uprisings Jan ‘11

NARSS (Cairo)

Helwan (Cairo)

EUN (Cairo)

23:59 Jan 28

23:59 Jan 27

12:00 Jan 27

• Impact varied: start time, recovery time, after effects• Egypt University Network (EUN) down least time

– NARSS via Alternet->Italy->Egypt, Helwan &EUN via PCCW Global

• Libya first went dark 06:00 Feb 19 for 3 days, then again on Mar 4th more permanently

• Algeria, Morocco, Tripoli not noticeable

=No pings respond

19

Average Round Trip Time (RTT)• Mainly a distance related, but also congestion (i.e. at

the edge)

• For real-time multimedia (H.323) traffic RTT: 0-300ms =Good, 300-600ms=Accceptable, and > 600ms= poor.


20

Minimum RTT history by region• Minimize effects of congestion and queuing


21 UNIMASWorkshop, Sarawak, Dec 2012

•GEOS (Geostationary Earth Orbit Satellite)–Good coverage, but expensive in $/Mbps–& long delays min RTT >450ms easy to spot

N.b. RTTs > 250 ms bad for VoIP

Impact of GEOS vs TerrestrialGEOSGEOS


Conversion history by country seen by min-RTT

23

Jitter• Mainly at edges, critical for real time: VoIP, gaming• Exponential improvement (factor 10 in 6 yrs)• The optimum amount of one way latency is 11 ms for keeping time in

music. – Above that delay and they tend to slow down. – >50-70 ms performances tended to completely fall apart.


• For real time haptic control and feedback for medical operations <=80ms is needed.

N. America, Europe, E Asia & Oceania < 1msAfrica, S. Asia & S.E. Asia worst off

24 Summer Joint TechsStanford, July 2012

Losses• Low (<1%) losses are good.• Real time impact due to recovery timeouts, e.g. echoing typing• Losses are mainly at the edge, so distance independent• Losses improving roughly exponentially, ~factor 100 in 12 years

24

Loss has Similar

behavior to thruput

• Best <0.1%: N. America, E. Asia, Europe, Australasia

• Worst> 1%:• Africa & C. Asia

Loss



Derived ThroughputDerived throughput ~ 8*1460/(RTT*sqrt(loss))

Mathis et. al

Europe, E. Asia & Australasia merging

Behind Europe:

4 yrs: Russia, 7 yrs:L America,

M East, SE Asia

11 yrs: India, C. Asia

13 yrs: Africa

26

• ITU metric, based on quality of a conversation– Originally people listen and give quality 1-5– Can derive from RTT, jitter and loss


MOSMean Opinion Score MOS)

• >=4 is good,

• 3-4 is fair,

• 2-3 is poor.

Important for VoIP

Usa

ble

From the PingER project http://www-iepm.slac.stanford.edu/pinger


Directness of connection (Alpha)• Alpha to allow for delays in network equipment &

indirectness of actual route. D = 1 way distance– Alpha = D(km) / (min_RTT[msec] * 100 [km/msec])

• If know lat/long of monitor and remote host then know D, so with min-RTT can estimate Alpha– Max(Alpha) =1 = direct (great circle) route and no

network delays– Alpha > 1 probably identifies bad lat/long

coordinates for hosts.– Low values typically mean very indirect route, or

satellite or slow connection (e.g. wireless)– Alpha typically ~ 0.45


Alpha worldwide

• Interest in Polar route with Global warming


Alpha=0.71A

lpha

=0.7

3

Alpha

=0.7

3SLAC

JP

AU

NZ

NSK.RU

TW0.180.16IN

DE

EG0.34

JP0.32

o.41

AU0.53

29

• Big improvements for C Asia, S Asia & Australasia


Directivity (Alpha) from SLAC to world


More stable year to year as add more hosts


Other metrics• Duplicate packets (try ping www.cern.ch, load

balancing?)

• Out of order packets (parallel paths)

• Conditional Loss Probability (non-random loss)

– one packet is lost the following packet is also lost– route change, loss of sync, spanning tree reconfig

• Maximum packet loss (useful for buffer bloat?)



More Information

• PingER web home page– http://www-iepm.slac.stanford.edu/pinger/

• Tutorial on network monitoring– http://www.slac.stanford.edu/comp/net/wan-mon/tutorial.html

• PingER data Explorer– www-iepm.slac.stanford.edu/pinger/explorer.html

• Telegeography submarine cable map– http://www.submarinecablemap.com/

32

S.E. Asia

• Just started mining early data

• Where does Malaysia sit

• How much variation in SE Asia

• Variation in Malaysia

• Troubles at UNIMAS

• Top and bottom 3 sites monitored in Malaysia


33

Malaysia vs Other Regions


34

Variation between SE Asian countries

• Factor of 10 between Singapore and Laos

• Singapore 4x better than next countries

• Exponentially improving with time

• On its ownSingaporeapproachesE Asia.


35

Avg-RTT, jitter & loss by Malay State• Need low values of all 3 metrics

• RTTs similar, big diffs in jitter & loss

• Allianze UniColl looks bad

• UTP next worst loss


Seen from SLAC, Nov 2012

36

Non lossy Malaysian hosts seen from SLAC Nov 2012


UNIMAS

MIMOS

MIMOS

UNISZA

Note monitoring host (SLAC) down

37

OCESB

Lo

ssy

ho

st s

een

fro

m S

LA

C N

ov

2012


UPSI

UTEM

MIU

AIU

Sabah

38

Diving deeper: packet loss Nov 27-28• Allianze University College unreachable• UTEM, MIU, UPSI, OCESB, AIU, SABAH experienced loss Nov

26• No PingER loss from the rest on Nov 26: Johor, Kelantan, KL,

Negeri Sembian, Sarawak, Terenggan


1930-midnight MST, backup?

UTEMLosses isolated, not correlated with large RTT

39

Another host, large RTTs correlate with time of day (note MST)


40

UNIMAS Jitter


UNIMAS to

MalaysiaJitter

AllianzeUniversity

College

Universiti TechnologiPetronas

41

Why not show UNIMAS to Malaysia more

• Big changes in RTT affect throughput especially for Kuching

• UNIMAS was seeing congestion – This would be seen everywhere– Turn on shaping– Removes loss &

day-night variations


2

1RT

T m

s

Background loss colors

SLAC to UNIMAS Oct-Nov 2012

42

Increase of capacity to UNIMAS from 200Mbps to 500Mps


43

Improvement


44

Unreachable Malaysian hosts

• Unreachable from SLAC Nov 1-26, 2012:1. 92% Allianze University College

2. 20% www.ocesb.com.my (Speedtest)

3. 17% Universiti Teknologi Petronas,Bandar Seri Iskandar

4. 4% University Malaysia Kelantan

• 100% Reachable– MIMOS, UNIMAS, Sultan Zainal Abidin University,

USIM, University Teknologi Malaysia, Sultan Idris University of Education



Demo

• Interactive demonstrations of the data mining capabilities of public data sources provided by organizations such as the UN and ITU coupled with monitoring data from PingER

• http://www-iepm.slac.stanford.edu/pinger/explorer.html


46

Comparison to UN ITU ICT Development Index


100

1000

10000

ICT Development Index from the UN International Telecommunications Union

2 4 6 810

Pin

gER

Der

ived

thr

ough

put

(kbi

ts/s

ec)

Bubble size = Population

47

More Information

• PingER web home page– http://www-iepm.slac.stanford.edu/pinger/

• Tutorial on network monitoring– http://www.slac.stanford.edu/comp/net/wan-mon/tutorial.html

• PingER data Explorer– www-iepm.slac.stanford.edu/pinger/explorer.html

• Invitation to set up a Monitoting host– www-iepm.slac.stanford.edu/pinger/letters/invite-

monitor.doc


48

Congestion at UNIMAS• SLAC to UNIMAS Nov 1st through Dec 6th

• Note the diurnal changes until shaping


Loss

RTT

Documents

PingER : Actively measuring the worldwide Internet’s end-to-end performance