In this recipe, we first add a remote SDN controller pointing to the ONOS controller and the switches—two SDN switches (s1 and s2) and on legacy switch (s5, marked by failMode='standalone'). We then add hosts and links with various properties. The link properties including bandwidth, loss rate, maximum queue size, delay, and speed up are modeled.

Once the network is built, the controller is started. The SDN switches s1 and s2 are started from the controller:

   net.get('s2').start([c0]) 
   net.get('s1').start([c0]) 
However, the legacy switch s5 does not support OpenFlow or any SDN protocols. Hence it is started on its own. 
   net.get('s5').start([]) 

However, s5 is still connected to another SDN switch s1, which acts as the core switch of the network. ONOS controls this network as it is emulated.