QoS on Besteffort IP Networks

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QoS on Best-effort IP Networks

• Les Cottrell SLAC
• www.slac.stanford.edu/grp/scs/net/talk/qos-itu-apr
  01/
• Presented at the Joint SG13/SG16 Workshop Panel
  Session "Achieving Multimedia QOS over IP-Based
  Networks" part of the ITU-T SG13/SG16 Workshop on
  IP Networking and Mediacom 2004, Geneva,
  Switzerland, April 25-27, 2001

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

• Measurement methodology
• Delay
• Loss
• Jitter
• Availability
• Summary

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PingER

• Measurements from
• 32 monitors in 14 countries
• Over 600 remote hosts
• Over 72 countries
• Over 3300 monitor-remote site pairs
• Measurements go back to Jan-95
• Reports on RTT, loss, reachability, jitter,
  reorders, duplicates
• Uses ubiquitous ping facility of TCP/IP
• Countries monitored
• Contain 78 of world population
• 99 of online users of Internet

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RTT from ESnet to Groups of Sites
RTT distance/(0.6c) hops router
delay Router delay queuing clocking in out
processing
ITU G.114 300 ms RTT limit for voice
20/year
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RTT Region to Region
OK White 0-64ms Green 64-128ms Yellow
128-256ms NOT OK Pink 256-512ms Red gt 512ms
OK within regions, N. America OK with Europe,
Japan
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RTT from California to world
Europe
E. Coast
Brazil
E. Coast US
W. Coast US
300ms
RTT (ms)
Europe S. America
30.6c
Longitude (degrees)
300ms
Frequency
Source Palo Alto CA, W. Coast
RTT (ms.)
Data from CAIDA Skitter project
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Loss seen from US to groups of Sites
50 improvement / year
ETSI DTR/TIPHON-05001 V1.2.5 threshold for good
speech
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Loss to world from US
Using year 2000, fraction of worlds
population/country from www.nua.ie/surveys/how_ma
ny_online/
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Losses between Regions
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Jitter from N. America to W. Europe
Jitter IQR(ipdv), where ipdv(i) RTT(i)
RTT(i-1) 214 pairs
ETSI DTR/TIPHON-05001 V1.2.5 (1998-09) good
speech lt 75ms jitter
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Jitter between regions
ETSI DTR/TIPHON-05001 V1.2.5 (1998-09)
125msMed
225msPoor
75msGood
Jitter varies with loading
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SLAC-CERNJitter
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Availability Outage Probability
Surveyor probes randomly 2/second Measure time
(Outage length) consecutive probes dont
get through Heavy tailed outage lengths (packet
loss not Poisson)
http//www-iepm.slac.stanford.edu/monitoring/surve
yor/outage.html
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More Information

• This talk
• www.slac.stanford.edu/grp/scs/net/talk/qos-itu-apr
  01/
• IEPM/PingER home site
• www-iepm.slac.stanford.edu/