Test steps

      1. Config IxNetwork with switches (first with 100) with linear topology and two hosts in the first and last switch.

      2. Start the controller with the features install.

      3. Start the OF protocol of the switch.

      4. Wait until the channel is established and Echo message interaction started.

      5. Start the capture of IxNetwork.

      6. Enable the traffic between this two hosts, wait until the hosts can ping through each other.

      7. Stop the capture, analyse the messages captured. Write down the time of the first packet_in message T1 and the time of the last flow mod message T2. Caculate the time of Datapath seted up T=T2-T1

      8. Clean the configuration of controllers and IxNetwork.

      9. Repeat test step 1-8 for three times.

      10. Restart the test with another number of switches.

Test Results

• Datapath Setup Time

  switches	First (ms)	Second (ms)	Third (ms)	Avg (ms)
  100	1200	1169	1164	1178
  200	1809	1745	1659	1738
  300	3100	3363	3357	3273
  400	5478	7171	7177	6609
  500	10983	12946	10624	11518
  600	30633	32603	46932	36723
  700	69950	68673	58760	65794
  800	131691	122576	142910	132392

After 800 switches, datapath can't setup in 5 minutes so we conclude that the maximum number is 800 switches.

• Histogram of Datapath Setup Time
  
  

As the histogram shown, the time increases significantly with the number of switches.