Bill Studenmund quoted me
> > I think Christos may have been getting at) it's at least not transparently
> > clear to me that the congestion control effects of dropping and declining are
> > identical.

and responded
> I think the point Jonathan was trying to make on this is that it doesn't 
> matter.

I think you are right that Jonathan was making that assumption.  The
assumption may even be right, but, as it was precisely my aim to point out,
it is not transparently self-evident.  An argument showing that it really
doesn't matter would convert making-an-assumption into making-a-point.

> The application called send() and the packet didn't go. To quote 
> the man page, "send(), sendto(), and sendmsg() are used to transmit a 
> message to another socket." That didn't happen. Thus it was a drop.

I understand the sense in which you are using the word 'drop'.  I'm reminding
you that there is another sense of the word 'drop', in which the send *did*
happen, in all respects that the sender can see, but the receiver did not
get the packet, and this is a sense commonly used in reasoning about best-
effort delivery systems.  If you stand far enough away, you can say both
senses are the same in that a completed message exchange didn't happen, but
that's only when you stand too far away to see the error recovery and
queueing properties of the protocols involved, and I'm not convinced those
are irrelevant to this thread.

-Chap