1 Measurements of Internet performance for NIIT, Pakistan Jan – Feb 2004 PingER From Les Cottrell,...
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Transcript of 1 Measurements of Internet performance for NIIT, Pakistan Jan – Feb 2004 PingER From Les Cottrell,...
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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