OF-CONFIG protocol for SDN southbound Interface Technology

In the SDN standard system developed by ONF, in addition to OpenFlow switch specification pairs, there is also a Protocol named OpenFlow Configuration and Management Protocol (OF-CONFIG) also needs to be concerned. As mentioned above, OpenFlow defines a kind of southbound interface in SDN network architecture, and proposes a method for the Controller to send a flow table to the OpenFlow switch to control the path of the data stream through the network, but there is no rule on how to manage and configure these network devices, and OF-CONFIG is proposed to solve this problem.

The essence of OF-CONFIG is to provide an open interface for remote configuration and control of the OpenFlow switch, but it does not affect the flow table content and data forwarding behavior, there is no high requirement for real-time. Specifically, items such as building a stream table and determining the data flow direction will be defined by the OpenFlow specification, for example, how to configure the controller IP address on the OpenFlow switch, how to enable/disable each port of the switch is done by the OF-CONFIG protocol.

All software and hardware (such as ports and queues) involved in data forwarding on the OpenFlow switch can be considered as network resources, and the role of OF-CONFIG is to manage these resources. Shows the relationship between a OF-CONFIG and OpenFlow.

The OF-CONFIG adds a Configuration node called the OpenFlow Configuration Point in the OpenFlow architecture. This node can be either a software process on the Controller or a traditional network management device, it manages the OpenFlow switch through the OF-CONFIG protocol, so the OF-CONFIG protocol is also a kind of southbound interface.

OF-CONFIG is an important technology in the implementation of SDN architecture proposed by ONF, which has a close relationship with OpenFlow. There is a close relationship between OF-CONFIG and OpenFlow, so with the evolution of the OpenFlow standard, the version of the OF-CONFIG is also synchronized with it.