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From Andrew McIntyre <fuzzylo...@sbcglobal.net>
Subject Re: Help detecting client disconnects for network server
Date Mon, 11 Oct 2004 07:13:03 GMT

On Oct 10, 2004, at 11:20 PM, Samuel Andrew McIntyre wrote:

> the default value for net.inet.tcp.keepidle on the Mac is 144s and the 
> interval for probing is only 1.5 secs

Taking a second look at those numbers, I realized that those are off 
from the expected numbers by a factor of 20 (144000=7200000/20, 
1500=75000/20). A look at tcp_timer.c in the Darwin source shows they 
are doing a conversion on the value.  It is still off by a factor of 2 
from what I would have expected (would have expected 72000 instead of 
144000 for a value of 2 hours), but it's likely i'm missing something. 
So, maybe Mac OS X isn't violating RFC1122, but the behavior described 
would still hold if our timeout value is above the keepalive value, 
whatever it may be.

Also good to note, I suppose, that the keepalive value may not actually 
be the length of time you expect, and setting the same value on 
different systems may yield different results.


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