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From: RW <list-freebsd-2004@morbius.sent.com>
To: FreeBSD - Questions <freebsd-questions@freebsd.org>
Date: Sat, 25 Mar 2006 02:09:09 +0000
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Subject: TCP delayed acks not being delayed?
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I have a 1MB/0.25Mb ADSL connection and have an IPFW rule to prioritize 
outgoing empty acks. If I download a single file with kget at 100 kbytes/s, I 
see that the rule gets hit at a rate of  50/s: ie a little under 1 empty-ack 
per incoming packet.

I have: 

net.inet.tcp.delacktime: 100
net.inet.tcp.delayed_ack: 1

which I thought should limit each TCP connection to <=10 empty acks per second