More issues with window sizing

[paul s. <pshields@NAVINI.com>]

On Solaris I get the following errors

$ iperf -s -w 64K
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 64.4 KByte (WARNING: requested 64.0 KByte)
------------------------------------------------------------

With the warning, I don't think it properly sets the window size because
performance is below expectations (less than running the same test between
two windows machines).

------
Also, I ma seeing performance issues with running multiple iperf sessions on
one machine. I need to start traffic from one machine going out to 150
different machines. Once I get past about 40 iperf clients on the Sun
server, the machine get very slow. Each iperf sessions is using about 2.3%
of the CPU. Is there something I can do to help this(besides adding more
endpoints which I am going to do).

This is while using iperf in UDP mode, streaming 64 byte packets at about
200K per client.

Thanks
Paul