On Wed, Sep 06, 2006 at 10:48:08AM -0400, Steven M. Bellovin wrote:
> The retransmissions are, I suspect, the key.  If TCP has to retransmit,
> it's because a packet or its acknowledgment got lost; TCP in turn
> interprets that as due to congestion and backs off.  The question, then,
> is why packets are getting lost.  Does 'netstat -i -d' show any drops on
> lo0?

It is apparently because the sending process sends segments after window,
which the receiving side discards.

Pavel