The following figure illustrates the controller. An ONF controller is an SDN controller that contains an OpenFlow® switch controller and an OpenFlow® config controller. These controllers are tightly bound: they share information models and state, through means that are not subject to standardization.
A communications channel is first established between the OF config controller and the OpenFlow® capable switch. This channel configures the logical channel between the OF switch controller and the OF logical switch. The OF config channel (or the separate config mechanism if OF-switch is supported, but not OF-config) is used for all further configuration of the OFCS, including instantiation of OF logical switches.
There is a single communications channel between an OF switch controller and an OFCS. The OFCS is responsible to demultiplex the channel into separate sub-channels to each logical switch. As configured through the OF config channel, the logical switch may further demultiplex its sub-channel into auxiliary channels.
