[ns] tcp modified to AIMD and AIPD problem.....

cheng pong lo n2689134@dec4000.cc.ncku.edu.tw
Sun Aug 18 05:16:40 2002


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hi, every seniors:

    i have some problems about NS simulation=20
   =20
    i try to simulate the aipd algorithm, i do not know what should be=20
    done to NS to simulate AIPD.
    (`a comparison of end-to-end congestion control algorithms : the =
case=20
    of AIMD and AIPD`, kang-wond lee,tae-eun kim,vaduvur bharghavan, =20
    infocom 2001)

    so i try to modify reno first. i let both ssthresh and cwnd become=20
    cwnd*(1 - beta*lossrate ), ( i try to estimate lossrate by sequence=20
    number) when three duplicate acks received every time.=20
    the result shows that, some tcp-aipd`s sending rate (cwnd/srtt)
    behave as semicircle. and there are many rectangles on this =
semicurcle.

    i try to modify cwnd only, and keep ssthresh as aimd (0.5).
    but the result is the same.
   =20
    have any senior do research about modifying congestion window(cwnd) =
when duplicate ack is received?
    could you tell me the detail modification please ,=20

                                                thank you

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<DIV><FONT size=3D4>hi, every seniors:</FONT></DIV>
<DIV><FONT size=3D4></FONT>&nbsp;</DIV>
<DIV><FONT size=3D4>&nbsp;&nbsp;&nbsp;&nbsp;i have some problems about =
NS=20
simulation </FONT></DIV>
<DIV>
<DIV align=3Djustify><FONT =
size=3D4>&nbsp;&nbsp;&nbsp;&nbsp;</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; i try to simulate =
the aipd=20
algorithm, i do not know what should be&nbsp;</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; done to NS to =
simulate=20
AIPD.</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; (`a comparison of =
end-to-end=20
congestion control algorithms : the case </FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; of AIMD and =
AIPD`, kang-wond=20
lee,tae-eun kim,vaduvur bharghavan,&nbsp;&nbsp;</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; infocom =
2001)</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4></FONT>&nbsp;</DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; so i try to =
modify reno=20
first. i let both ssthresh and cwnd become </FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; cwnd*(1 - =
beta*lossrate ),=20
(&nbsp;i try to estimate lossrate&nbsp;by sequence </FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; number) when =
three duplicate=20
acks received every time. </FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; the result shows =
that, some=20
tcp-aipd`s sending rate (cwnd/srtt)</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; behave as =
semicircle. and=20
there are many rectangles on this semicurcle.</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4></FONT>&nbsp;</DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; i try to modify =
cwnd only,=20
and keep ssthresh as aimd (0.5).</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; but the result is =
the=20
same.</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; </FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; have any senior =
do research=20
about modifying congestion window(cwnd) when duplicate ack is=20
received?</FONT></DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; could you tell me =
the detail=20
modification please , </FONT></DIV>
<DIV align=3Djustify><FONT size=3D4></FONT>&nbsp;</DIV>
<DIV align=3Djustify><FONT size=3D4>&nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; thank =
you</FONT></DIV></DIV></BODY></HTML>

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