wierd dsl performance with -CURRENT
julian at elischer.org
Wed Jul 9 14:00:29 PDT 2003
On Wed, 9 Jul 2003, Kenneth Culver wrote:
> > Can you do a
> > 'netstat -s -p tcp >> tcpstats' before and after the transfer?
> > This should tell us if there were retransmits etc. It could be a
> > difference in minimum rtt values or a congestion issue that results in
> > timeout for our stack but some other recovery mechanism with other stacks.
> Here is the output of the netstat before and after transferring "kern.flp"
> for FreeBSD 5.1:
> 35600 packets received
> 1220 out-of-order packets (1657153 bytes)
> This is after:
> 36688 packets received
> 1298 out-of-order packets (1770089 bytes)
This is the only thing that is of any interest..
and it could only really be if the etherent driver was re-ordering
possibly FreeBSD 5 might react more to out-of-order packets..
capture a download with tcpdump
and save it (ascii version) to a file using the -ttt option to get
look of any large values in the timestamps and see if there is anything
before that indicates a lost packet or a re-ordered one or something
(or a retransmitted ack)
The key is to find the gap in the arriving packets and figure out
what caused it..
> Could this be something my ISP did that causes a problem for FreeBSD and
> not the other OS's?
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