Good network traffic visualization tools ?

[Lechner, David]

I am investigating the performance of a multi-component software program on
a cluster wrt various HW and network configurations -
Can anyone suggest good tools to help monitor network utilization?  I
understand that SNMP enabled switches allow doing this, but I am using
generic products now not branded products with lots of software support.  So
far I have looked at KSniffer, Cricket, Cheops, IPTraf, and NTop  - 
I am using a mix of programs and need to measure capability of distributed
programs that use direct sockets without MPI - we'd like to see the traffic
monitored "real-time" via some color-coded matrix screen that shows traffic
BW between nodes - even if it is just a table of values for all traffic
within a cluster though then that would be good enough for now - we will
snap that data into a vis. tool (an approach common to many of the tools I
mention above).
I also need Windows support as well as Linux - 

Thanks in advance -  
Dave Lechner.