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Measurements of Internet performance for NIIT, Pakistan

Jan – Feb 2004

PingER

From Les Cottrell, SLACFor presentation by Prof. Arshad Ali, NIIT

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TCP throughput measured from N. America to World Regions

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10

100

1000

10000

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Jan-

03

Der

ived

TC

P th

roug

hput

in

KB

ytes

/sec

1

10

100

1000

10000

China (13)

S.E. Europe (21)

Europe(150

Canada (27)

Russia(17)

Edu (141)

Latin America (37)

India(7) Africa (1)

Mid East (16)

80% Improvement/year~ factor of 10 in 4 years

C. Asia (8)

Results: Worldwide performance

• Performance is improving• Developed world

improving factor of 10 in 4-5 years

• S.E. Europe, C.Asia Russia, catching up

• India & Africa worse off & falling behind

• Developing world 3-10 years behind

• Many institutes in developing world have less performance than a household in N. America or Europe!!

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To Pakistan performance

Karachi

NIIT/Rawalpindi

Islamabad

Lahore

Loss %

RTT ms

Routes: ESnet (hops 3-6) - SNVSINGTEL (7-12) - KarachiPakistan Telecom

KarachiRawalpindi

Routes: ESnet (hops 3-6) - SNVSINGTEL (7-12) - KarachiPakistan Telecom

KarachiLahore

Routes: ESnet (hops 3-8) - DCATT (9-21) - Karachi

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From Pakistan Performance

Note similarities, probably due to common bottleneck, probably in Pakistan

NIIT to SLAC

NIIT to CERN

Route: Pakistan Telecom (2-5) Rawalpindi, KarachiSingTel (6-10)ESnet (11-14) - PAIX

Route: Pakistan Telecom (2-5) Rawalpindi, KarachiConcert (6-9) LondonDataTAG (11-12) .de

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NIIT performance from U.S. (SLAC)

Ping RTT & Loss

Nb. Heavy losses during congested day-times

Bandwidth measurements using packet pair dispersion & TCP (Jan 2004)abing (pkt-pair dispersion):Average To NIIT: ~350Kbits/s From NIIT: ~365 Kbits/sIperf/TCP (with SLAC): Average: To NIIT: ~320Kbits/s From NIIT: ~330Kbits/sIperf/TCP (with CERN): Average: To NIIT: ~270Kbits/s From NIIT: ~300Kbits/sCan also derive throughput (assuming standard TCP) from RTT & loss (monthly) using: BW~1.2*S(1460B)/(RTT*sqrt(loss) ~ 260Kbits/s (SLAC to NIIT)

~ 630Kbits/s (NIIT to SLAC | CERN)Nominal path bottleneck capacity 364 Kbits/s

Preliminary results, started measurements end Dec 2003.

Avg daily:

loss~1-2%,

RTT~320ms

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Available Bandwidth (Feb ‘04 after upgrade)

• green line is the bandwidth capacity of current bottleneck– deduced from the minimum

packet separation

• blue line is available bandwidth = capacity-cross-traffic.

• Use available bandwidth estimator (abing)– Uses packet pair dispersion– Low impact, 40*1450Byte packets– Repeat once/minute– Client at SLAC, mirror/server at NIIT

• Iperf confirms with:– 948Kbps (2streams), – 952Kbps (4streams),– 1042Kbps (10streams)

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To NCP Pakistan• Cannot use PingER to measure to ncp.edu.pk

– Pings blocked at FLAG router (62.216.145.154, AS15412) on way to Comsats (Pakistani ISP)

• Working with NCP to try and resolve– Trying to contact FLAG

• Using abing instead– Indicates 2Mbps– But link is 384Kbps

• Iperf shows 235 - 245 Kbps• Rate limiting or shaping?

~ 2MBits/s, but link is 384KbpsLooking for discrepancy

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Within Pakistan• SLAC – Karachi U:

– ESnet (hops 3-8) – DC ATT (9-21) – Karachi

• SLAC – NIIT RawalpindiI: – ESnet (hops 3-6) – SNV, SINGTEL (7-12) – Karachi, Pakistan Telecom

Karachi-Rawalpindi

• SLAC - U Lahore, similar to NIIT• SLAC – NSC:

– ESnet (hops 1-6), C&W (7-11) Santa Clara – NY, FLAG (12-16) NY – London – Karlsruhe, Comsats

• NIIT – NSC (Rawalpindi – Islamabad) few miles apart, –No peering in Pakistan, can this be changed?–Route goes via England:

•PIE (hops 1-5), Concert (6-9)- London, FLAG (10-14) London – Karachi, Comsats (15)

–Takes longer than to SLAC

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Conclusions• Big performance differences to sites, depend on ISP

(at least 3 ISPs seen for Pakistan A&R sites)• To NIIT:

– Before upgrade got about 300Kbps - 380Kbps at best – After upgrade get 1 Mbps, as expected – The bottleneck appears 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

have been be marginal at best before upgrade, since upgrade has been very successful.

• No peering Pakistan between NIIT and NSC

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Bulk Data Transfer• Transfer time to send a file of various sizes between 2 sites

with given capacity – assume can utilize 50% of capacity– format hours:mins:seconds

PingER

File size

Typical BaBar file sizes 500MB-1GB

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Interactive Use• Voice needs RTT < 250ms or else listener does not know

when to speak• RTT > 400ms makes productive interactive work such as

interactive telnet/X-windows style typing difficult– Screen does not match the keyboard, especially when correcting text

• Losses:– Losses > 10% TCP connections fail– Losses >4-6% make video conferencing unintelligible for non-native

language speakers– Losses of > 3-5% make TCP perform badly– Random loss of 2.5% will make Voice over IP annoying every 30

seconds or so– More realistic burst losses will cause VoIP to be annoying at >1%

losses

PingER

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More information• NUST Institute of Information Technology (NIIT)

– http://www.niit.edu.pk/

• PingER project– http://www-iepm.slac.stanford.edu/pinger/

• ABwE available bandwidth estimator– www-iepm.slac.stanford.edu/bw/abwe/abwe-cf-iperf.html