A word of warning to anyone using qnet and modern Cisco switches.

Unless your switch support flow control, under heavy network traffic qnet data exchange will suffer from very long and 
misterious delay.  A 1Meg block of data taking a seconds to be transfered, a pulses taking 5 seconds (yes 5) to make it 
to another machine and so on.

I'm told recent model of Cisco switches only support partial flow control which is not enough to stop a network card 
from transmitting data if the switch is unable to forward it, qnet doesn't like this at all.  

To me that basically means qnet is not "reliable" (we can all argue on what reliable means but not now please) when used
 on switches that do not support flow control.  Apparently Cisco considers flow control to be old school and decided to 
drop the feature all together.