Lecture 9Characteristics of Networked Game

Traffic

22 March 2010

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WebFile TransferBitTorrentSkype Calls

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Understanding network traffic is crucial to traffic engineering

and protocol design

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What are the characteristic of traffic generated by games?

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data rate packet size

UDP or TCPpattern

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Differences betweenRTSFPSRPG

?

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Counter Strike

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20,000servers

as of May 2002

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3rdlargest source of UDP packets(behind DNS and RealAudio)

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Centralized Architecture

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32players supported

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3minutes per round

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30minutes per map

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Traffic includes

state updatestext messages

voice:

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How to collect packet traces?

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Run own Counter Strike’s server

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Collect packets over one week

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5886different clients

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500million packets analyzed

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500million packets analyzed

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542 kbps

mean out-going bandwidth

341 kbps

mean in-coming bandwidth

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50 msperiodic broadcast from server

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80.3average packet size in bytes

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39.72average in-

coming packet size in bytes

129.51average out-going packet size in bytes

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small packets(< 50 bytes)

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periodic

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predictable

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Shen Zhou Online

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20hours of traces

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112,369connections

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58terra bytes of data

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36%of packets are

23bytes

52%of packets are

27bytes

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7kbps of bandwidth on average

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200 msperiodic broadcast from server

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“flash crowd” effects

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even smaller packets

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small bandwidth

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periodic

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predictable

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temporal locality

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spatial locality

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