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Re: [tcpm] Tuning TCP parameters for the 21st century

Joe Touch <touch@ISI.EDU> Wed, 15 July 2009 14:34 UTC

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Date: Wed, 15 Jul 2009 07:25:00 -0700
From: Joe Touch <touch@ISI.EDU>
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Subject: Re: [tcpm] Tuning TCP parameters for the 21st century
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Jerry Chu wrote:
...
>> We're taking one more look at T/TCP as well (probably need to start a different
>> mail thread on T/TCP too).

T/TCP is deprecated due to a fairly large security issue that has not
been solved, AFAIK. It'd be useful to have a solution to that issue
before proceeding with it as an approach.

...
>> The SYN/SYN-ACK retransmission rate we measured turned out to be >> 1%
>> in many cases (a bit surprising to us) hence the benefit.

That points to some other problem going on. As a packet loss rate,
that's quite high and causes problems elsewhere in TCP. It would be
useful to understand where the drops are and why. Retransmitting SYNs to
a busy endpoint whose queue is overflowing doesn't help things, e.g.

Joe
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