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How can I find the type of TCP running on my Mac OS X? (TCP Reno, Fast TCP, ...)

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Not sure what you mean by type of TCP running. Can you explain what you are looking for? – Jim Deville Nov 4 '09 at 6:57
how congestion control is implemented in TCP? for example, TCP reno, Fast TCP, ... – mali Nov 4 '09 at 7:33
up vote 5 down vote accepted

Mac OS X apparently supports SACKs, making Reno obsolete...

net.inet.tcp.sack: 1


net.inet.tcp.newreno: 0

(from sysctl net | grep net.inet.tcp)

More here.

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If it is congestion control implementation you need to identify,
it might be easier to you can also look at the TCP packet stream from the machine.
Here is a StackOverflow question on how to 'fingerprint' TCP Congestion control algorithm.

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@TheDownVoter, a brief explanation for the down-vote will be highly appreciated. – nik Nov 4 '09 at 13:02

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