Send 8G files from sdn-a1 to sdn-b1 and sdn-a2 to sdn-b3 (b2 is still AWOL) while monitoring the rate of change of the SNMP counters for ports in switches OF-1 and OF-2 in from sdn-a1, between the switches, and out to sdn-b1 and the same for sdn-a2 -> b3.  The SNMP sampling rate is once/10 seconds, and the difference to the counters is calculated in the spreadsheet.
The files were sent starting at 11:25:48.

During that test, 700 OpenFlow rules per second were pushed, starting at 11:30:27.
These graphs are in order, from sdn-a1 and a2 to switch of-1 to switch of-2 to sdn-b1 and b3.