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WWW and World Wide Wait: Is it Forever? Hanoch Levy School of Computer Science Tel-Aviv University...
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Transcript of WWW and World Wide Wait: Is it Forever? Hanoch Levy School of Computer Science Tel-Aviv University...
WWW and World Wide Wait:Is it Forever?
Hanoch LevySchool of Computer Science
Tel-Aviv University
November 2000
World Wide Wait
www.xyz.com
Questions (W*)
• Do We Wait? • Where We Wait?• When We wait? • hoW much We Wait? • Why We Wait?• Why Telephone is so great and Web is not? • Will We Wait?
Waiting in Israel
• Our experience: long…• Short Experiment:
– Several sites at non-peak time– 70 KB pages – ISDN line (8 Kbytes/sec)– Avg wait time : 15 seconds– Peak time: worse
Waiting in the World (US)
• Source: An index of 40 leading Business Web site home pages down-load time (Keynote)
• Method:– Monday -Friday every 15 minutes between 6 am
and noon Pacific time– Around 50 agents located in metropolitan areas of
the United States.
Good News Index of Keynote Business 40 1999-2000
Better(?) NewsKeynote Index of Business 40 1998-99
Butt…Keynote Index of Consumer 40 – current
How come?
• Source: An index of 40 leading Consumer Web site home pages down-load time.
• Method:– Sunday – Saturday, every 1 hour,
between 5Am to 9Pm pacific time. – Around 50 agents in US.
• Difference: Sites + peak time
Comparison consumer vs. business
Where is the problem?
• Used to put the blame on the modem speed.• Now modems are faster• Problem is moving into the net:
– Internet service providers– Backbones– Mostly at switches
“Bandwidth like Water”?
• Claims (already 2-3 years old): – We have coming ADSL/Cable, Fiber Optics,
WDM, Tera-bits,…. – “bandwidth like water” no problem.
Answers
• They are here and still we wait…• “Free resource” paradox:
– If a resource is “free”, its doomed to be consumed!
– NAPSTER + alike: • Program to download songs/videos from other
computers (share). • 1 song = 60-100 Web pages!!• Traffic takes 30% or more in some places
(universities).
How Come Telephone is so great?
• Telephone : – old– Very uniform (all calls are alike)– Bounded (one cannot talk more than 24 hours/day)– System polices customers.
• Web:– New and dynamic – Services vary heavily (telephony, web, email, files).– User can request 100 Mbytes in a few clicks.– Little accountability (encourages greediness [pre-
fetch]).
How Come Telephone is so great? (2)
• Telephone : – Smooth traffic
• Web:– Very bursty traffic– Self-Similar / long tail – One request can generate a lot of data!!! – Need special controls!
t
t
What is needed?
1) Separate and prioritize applications– E.g.: voice > Web > Email.
2) Users / applications should be accountable– Cannot ask the network to bring you 100 songs
“for free”.– Will the $20/ month service fee hold?
What is being done today?
• Much activity (umbrella of Quality of Service)
• Current solutions:– Partial (part of the net)– Separation and prioritization– Accountability?
• Much forward looking work
Back to Questions
• Do We Wait? YES!• Where We Wait? Here, US,…• When We wait? Consumer-time, variable!!!
• hoW much We Wait? Yet, too much• Why We Wait? Little control • Why Telephone is so great and Web is not? • Will We Wait? At least for a while..
The End
Keynote Index of Business 40 1997-1998
Detailed Comparison (in seconds)
business consumer
Yahoo .67 4.74Lycos 1.06 6.76Apple 1.21Schwab 1.30 8.46FedEx 1.54
Worst 9.8 45.47
Index (avg 40) 3.28 16.84
Detailed time measures