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<div class="moz-cite-prefix">Am 19.05.2014 00:26, schrieb Vint Cerf:<br>
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<div dir="ltr">i think this is not an adequate analysis. Delay
variations between A, S, B and C might produce different
timeouts even if the RTT measurement algorithms are the same.
"fair"is not a simple notion in the dynamic and variable world
of the Internet.</div>
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<br>
On the one hand, I agree. On the other: You put in question
basically all phd theses on congestion control from the last 20
years.<br>
<br>
I just had a look at the ns2 code, I always (if unsaid) assumed, it
did go back n as retransmission strategy. (And from what I've seen 5
minutes ago, it apparently does. However, I should take the time to
have a closer look at the code.)<br>
<br>
=> Quite a lot of work in the past apparently made quite strong
assumptions, which may simply not hold in any cases,<br>
=> many phd-theses were theses on "ns2" but not on "TCP".<br>
<br>
<br>
What you say is no contradiction to my analysis. What you say is
that an identical rtt measurement algorithm may be insufficient to
produce "faire shares". (The term is not my invention, btw.)<br>
<br>
<br>
Detlef <br>
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<div>v</div>
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<div class="gmail_quote">On Sun, May 18, 2014 at 5:49 PM, Detlef
Bosau <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:detlef.bosau@web.de" target="_blank">detlef.bosau@web.de</a>></span>
wrote:<br>
<blockquote class="gmail_quote">Just to make my thoughts more
clear.<br>
<br>
Let A,B,C end nodes, S some switch.<br>
<br>
A<br>
\<br>
S---------------------------------C<br>
/<br>
B<br>
<br>
Assume one data flow from a to C, a competing one from B to
C.<br>
<br>
I expect that it makes a difference, whether both TCPs
employ the same<br>
RTO scheme or, e.g. A, uses a more aggressive one that does
earlier<br>
retransmissions than its competitor. At least when we expect
both TCPs<br>
to use a fair share of resources, both TCPs should employ
the same scheme.<br>
<br>
Do you agree?<br>
<div class="HOEnZb">
<div class="h5"><br>
Detlef<br>
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<pre class="moz-signature" cols="72">--
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Detlef Bosau
Galileistraße 30
70565 Stuttgart Tel.: +49 711 5208031
mobile: +49 172 6819937
skype: detlef.bosau
ICQ: 566129673
<a class="moz-txt-link-abbreviated" href="mailto:detlef.bosau@web.de">detlef.bosau@web.de</a> <a class="moz-txt-link-freetext" href="http://www.detlef-bosau.de">http://www.detlef-bosau.de</a>
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