Les Cottrell SLAC University of Helwan Egypt Sept 18 Oct 3 2010 wwwslacstanfordedugrpscsnettalk10internetperformppt 2 Overview Internet characteristics Users capacities satellites packet sizes protocols routing flows ID: 618510
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Slide1
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How is the Internet Performing?
Les Cottrell – SLACUniversity of Helwan / Egypt, Sept 18 – Oct 3, 2010
www.slac.stanford.edu/grp/scs/net/talk10/internet-perform.pptSlide2
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Overview
Internet characteristicsUsers, capacities, satellites, packet sizes, protocols, routing, flowsHow is it used apps etc.How the Internet worldwide is performing as seen by various measurements and metrics Application requirementsSlide3
USERS
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Internet Usage growth ‘95-’10
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95 00 05 09
Millions of Users
Penetration %
0 200 400 600
Asia
Europe
N Amer
L Amer
Africa
M East
Austrlasia
N America
Australia
Europe
L America
M East
Asia
Africa
World
0 20% 50% 80%
Millions of users
Year
1500
1000
500Slide5
Example: China
China not connected to the Internet until May 19941st permanent IHEP/Beijing used satellite via SLACwww.computerworld.com.au/article/128099/china_celebrates_10_years_being_connected_internet
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Where are they
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Internet city connections
Internet Users 2002
2.8% growth/year
~¼ world pop uses Internet
Developed world saturating
Developing catching up
73% penetration US
43% users from AsiaSlide7
Capacities
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What have they got?
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Capacity
From Telegeography
CapacitySlide9
Who is still on Satellite
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Terrestrial
GEOS
Min RTT (ms)
GEOS (Geostationary Earth Orbit Satellite)
good coverage, but expensive in $/Mbps
broadband costs 50 times that in US, >800% of monthly salary c.f. 20% in US
AND long delays min RTT > 450ms, usually much larger due to congestion
Easy to spot
Clear signatureSlide10
Packet sizes & types
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Packet size
primarily 3 sizes: WHY?
Packet size (bytes)
Cu,mulative probability %
Packets
Bytes
Mean ~ 420Bytes, median ~ 80Bytes
Measured Feb 2000 at Ames Internet eXchange
~ 84M packets, < 0.05% fragmented
close to minimum=telnet and ACKs, 1500 (max Ethernet payload, e.g. FTP, HTTP); ~ 560Bytes for TCP implementations not using max transmission unit discovery Slide12
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Internet protocol useThere are 3 main protocols in use on the Internet:
UDP (connectionless datagrams, best effort delivery), TCP (Connection oriented, “guaranteed” delivery in order)ICMP (Control Message protocol)
Time Feb-May 2001
Flows/10min
In
Out
TCP dominates today
SLAC protocol flows
TCP
UDP
ICMPSlide13
Routing
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HopsHop counts seen from 4 Skitter sites (Japan, S. Cal, N. Cal, E. Canada, i.e. 10-15 hops on average
Hop Count
Weak RTT dependence
on hop count
95%
50%
5%
RTT
HopsSlide15
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Richness of connectivity
Angle = longitude of AS HQ in whois recordsRadius=1-log(outdegree(AS)+1)/(maxoutdegree + 1)Outdegree = number of next Hops As’ accepting traffic
Deeper blue & red more connections
All except 1 of top 15 AS’ are in US, exception in CanadaFew links between ISPs in Europe and AsiaSlide16
Today’s routing less via US
www.nytimes.com/2008/08/30/business/30pipes.html
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Invented in US
1st 30 yrs most traffic thru US
70%=>20% in 10yrs
No central control
Patriot act=>store info outside US
China, India, Japan making larger investments
More level playing field
Harder for CIA!Slide17
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Routes are not symmetric
Min, 50% & 90% RTT measured by SurveyorNotice big differences in RTTsMay be due to different paths in the 2 directions or to different loading
Advanced to U. Chicago
RTT ms
RTT ms
U. Chicago to AdvancedSlide18
Flows
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Flow sizes
Heavy tailed, in ~ out, UDP flows shorter than TCP, packet~bytes75% TCP-in < 5kBytes, 75% TCP-out < 1.5kBytes (<10pkts)UDP 80% < 600Bytes (75% < 3 pkts), ~10 * more TCP than UDPTop UDP = AFS (>55%), Real(~25%), SNMP(~1.4%)Can roughly characterize as power law with slope & intercept
SNMP
Real
A/V
AFS
file
serverSlide20
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Flow lengths60% of TCP flows less than 1 second
Would expect TCP streams longer lived But 60% of UDP flows over 10 seconds, maybe due to heavy use of AFS at SLACAnother (CAIDA) study indicates UDP flows are shorter than TCP flows
TCP outbound flows
Active time in secs
Measured by Netflow
flows tied off at 30 minsSlide21
Applications
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Usage
P2p hit by RIAA law suitsMoving to video, social networkingVideo on demand double/2 years ’08-’13iPhones (only peripherally a phone)Mobile traffic doubles each year
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Yahoo
Google
Facebook
YouTub
eSlide23
Growth of Video
P2P traffic, still the largest share of Internet traffic today, will decrease as a percentage of overall Internet traffic.
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Internet video streaming and downloads are beginning to take a larger share of bandwidth, and will grow to nearly 60 percent of all consumer Internet traffic in 2014.Slide24
How Internet is used & when
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Enterprise
& tier 1
asert.arbornetworks.com/2009/08/the-internet-after-dark
Slide25
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Web use characteristics
Size of web objects varies from site to site, server to server and by time of day. Typical medians in 2000 varied from 1500 to 4000 bytesAlso varies by object type, e.g. medians formovies few 100KB to MBs, postscript & audio few 100KB, text, html, applets and images few thousand KB
Bytes
Size of average web page tripled in 5 years 2003-2008
www.websiteoptimization.com/speed/tweak/average-web-page/
Slide26
Why increasing
New users (easier for user, more coverage)New apps: You-Tube, climate modeling …New tools: manual(hand tuned) Automatic generationWeb 2: Ajax, Javascript, CSS
Broadband more elaborate/attractive designs possible26
desktop to web apps
e.g. mail, calendars, photo albums, games...Slide27
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Log Plot of ESnet Monthly Accepted Traffic, January 1990 – December 2008
Impact on backbones: e.g. Current and Historical
ESnet
Traffic Patterns
Terabytes / month
Oct 1993
1 TBy/mo.
Aug 1990
100 MBy/mo.
Jul 1998
10 TBy/mo.
38 months
57 months
40 months
Nov 2001
100 TBy/mo.
Apr 2006
1 PBy/mo.
53 months
ESnet Traffic Increases by
10X Every 47 Months
, on Average
July 2010
10 PBy/mo.Slide28
Performance by Metric
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What does performance depend on?End-to end internet performance seen by applications depends on:
round trip timespacket lossjitterreachabilitybottleneck bandwidthimplementation/configurationsapplication requirementsData transmitted in packetsSlide30
msec.
ITU G.114 300 ms RTT limit for voice
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RTT from SLAC to the World
RTT ~ distance/(0.6*c) + hops * router delay
Router delay = queuing + clocking in & out + processing
2/3 countries of world Ok for voice, rest mainly in Africa
What is the problem with > 300ms?Slide31
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RTT from California to world
Longitude (degrees)
300ms
300ms
RTT (ms.)
Frequency
RTT (ms)
Source = Palo Alto CA, W. Coast
E. Coast US
W. Coast US
Europe & S. America
Europe
0.3*0.6c
Brazil
E. Coast
Data from CAIDA Skitter project
WHY these distributions?Slide32
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Longitude
RTT(ms)
Seen from Japan
RTT from Japan to worldSlide33
Jitter
Variability of RTT, many ways to measure“Jitter” = IQR(ipdv); ipdv(i) =RTT(i) – RTT(i-1)Usually at edges, so ~distance independentImpacts smooth flows e.g. VoIP, video, real-timeHaptics (surgery) < 1ms; H.323 <40ms with buffer
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Internet Jitter seen from SLAC to World Sep’08
Can improve
voice with de-jitter buffer, e.g. 70msto smooth theflow
But….Slide34
Losses
On good lines usually congestionWireless dB loss, net devicesUsually last mile
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Distance independent
Big effect
Realtime, games, Voice, typing echo
1% loss VoIP annoyingSlide35
Derived Throughput
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Behind Europe5 Yrs: Russia,
Latin America, Mid East 6 Yrs: SE Asia
9 Yrs: South Asia12 Yrs: Cent. Asia
16 Yrs: Africa
Central Asia, and Africa are in Danger of Falling Even Farther behind
In 10 years at the current rate Africa will be 1000 times worse than Europe
Derived throughput ~ 8 * 1460 /(RTT * sqrt(loss))
Mathis et. al
1993Slide36
Where is best Throughput?
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Voice over IP
Affected by:Loss, RTT, Jitter, Quality measured by Mean Opinion Score (MOS)
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Can convert from RTT, loss & jitter to MOS
MOS values: 1=bad; 2=poor; 3=fair; 4=good; 5=excellent.
Typical reasonable range for Voice over IP (VoIP) is 3.5 to 4.2.Russia and
L.America
improved dramatically in 2000-2002 as moved from GEOS to terrestrial.
US, Europe, E. Asia, Russia and the M East (all above MOS = 3.5) good. S.E. Asia marginal, S. Asia need a lot of patience
C. Asia and Africa are pretty much out of the question in general.Slide38
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Application requirements
Based on ITU Y1541 & Stanford (Haptics)The VoIP loss of 10^-3 used to be 0.25 but that assumed random flat lossactual loss is often burstyTail drop in routersSync loss in circuits, bridge spanning tree reconfiguration, route changes
Application
Real
timeVoIPWAN connectivity
Web free services
Stream video
Haptics
(remote
surgery)
1 way delay
150ms
150ms
1000ms
undefined
400ms
160ms
‘jitter”
50ms
1000ms
undefined
17ms
1ms
Loss
10
-3
10
-3
10-3
undefined
10
-5
0.1Slide39
What’s next
Mobile devices40G (transAtlantic, US) & 100Gb backbonesOn demand dynamic dedicated services (layers 1 & 2)Reserve a path at some bandwidth for some timeUse QoS to deliverHEP, Radio Astronomy, climate research
IPv639Slide40
Questions & more study
www.internetworld.stats.comwww-iepm.slac.stanford.edu/
pingerwww.slac.stanford.edu/comp/net/wan-mon/tutorial.html www.slac.stanford.edu/xorg/icfa/icfa-net-paper-jan09/report-jan09.doc
http://www.cablemap.info/
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Compare with Development Indices
Abv
.Name
Organization
Countries
Date of Data
GDP
Gross Domestic Product per capita
CIA
229
2001-2006
HDI
Human Development Index
UNDP
175
2004
DAI
Digital Access Index
ITU
180
1995-2003
NRI
Network Readiness Index
World Economic Forum
120
2007
TAI
Technology Achievement Index
UNDP
72
1995-2000
DOI
Digital Index
ITU
180
2004-2005
OI
Index
ITU
139
1996-2003
CPI
Corruption Perception Index
Transparency Organization
180
2007
41
Choose most: up-to-date, countries, important factors
HDI & DOI