<br><div class="gmail_quote"><p><span lang="EN-US">Hi!<br></span></p><p><span lang="EN-US">I did a benchmark of throughput in wireless
network with different UDP packet size. The UDP packet size is from 2K bytes to
40k bytes. The MTU is set to be 2348 bytes. <br></span></p><p><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 11"><meta name="Originator" content="Microsoft Word 11"><link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Cwp%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><style>
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</p><p class="MsoNormal" style="margin-left: 36pt; text-indent: -18pt;"><span style="" lang="EN-US"><span style="">1)<span style="font-family: "Times New Roman"; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">
</span></span></span><span style="" lang="EN-US">test</span><span lang="EN-US"> measure</span><span style="" lang="EN-US">s</span><span lang="EN-US"> the </span><span style="" lang="EN-US">throughput</span><span lang="EN-US"> over the wireless channel while varying the packet size from </span><span style="" lang="EN-US">20</span><span lang="EN-US">00 to </span><span style="" lang="EN-US">40</span><span lang="EN-US">000
bytes by 100</span><span style="" lang="EN-US">0</span><span lang="EN-US"> byte intervals.</span><span style="" lang="EN-US"> In this test, e</span><span lang="EN-US">very </span><span style="" lang="EN-US">test run</span><span lang="EN-US"> consists of
two steps:</span></p>
<p class="MsoNormal" style="margin-left: 54pt; text-indent: -18pt;"><span style="" lang="EN-US"><span style="">1.<span style="font-family: "Times New Roman"; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">
</span></span></span><span lang="EN-US">Se</span><span style="" lang="EN-US">nd</span><span lang="EN-US"> packet</span><span style="" lang="EN-US">s for 12</span><span lang="EN-US">0s.
</span></p>
<p class="MsoNormal" style="margin-left: 54pt; text-indent: -18pt;"><span style="" lang="EN-US"><span style="">2.<span style="font-family: "Times New Roman"; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">
</span></span></span><span lang="EN-US">Record the result</span><span style="" lang="EN-US"> and increase the packet size by
1000 bytes.<span style=""> </span></span><span lang="EN-US">.<span style=""> </span></span></p>
<p class="MsoNormal" style="margin-left: 21pt; text-indent: 15.75pt;"><span lang="EN-US">Each test run
last</span><span style="" lang="EN-US">s</span><span lang="EN-US"> for</span><span style="" lang="EN-US">12</span><span lang="EN-US">0 seconds</span><span style="" lang="EN-US">.
The test run begins at size 1000 bytes and ends at size 40000 bytes. 39</span><span lang="EN-US"> test runs </span><span style="" lang="EN-US">are
</span><span lang="EN-US">conducted. </span><span style="" lang="EN-US">If the size is bigger than MTU, the packets will be fragmented. <br></span></p>The result figure is shown in attachment.
<p></p>
<p><span lang="EN-US">The benchmark platform I use contains two buffalo
wireless g router. One router is the sender, and one is the receiver. The
operating system in them is Linux with 2.4.7 version kernel.</span></p>
<p><span lang="EN-US">The result of the benchmark confuses me. From
the following figure we can see that the throughput is highest when the UDP
packet size is about 20k<span></span><span> </span>bytes which is much
bigger than the MTU. I guess it is because of the buffer in the system, but I
am not quite sure. Do you see it before? Could you explain it?</span></p><p><br><span lang="EN-US"></span></p><p><span lang="EN-US">regards,</span></p><p><span lang="EN-US">Peng<br>
</span></p>
</div><br>