Open flow is a multivendor open standard which is introduced by open networking foundation (ONF). It is an important protocol which is used in the implementation of SDN in networking devices. An open flow architecture outlines an interface between an open flow controller and an open flow switch. Open flow architecture works appropriately and connects open flow channel to a controller which is outside the network. It performs effective functionality via data packet lookup and forwarding. As per my opinion, open flow protocol is one of the major protocol that enables higher network functionalities.
Open flow architecture is defined by open networking foundation for the implementation of SDN. Open flow architecture consists of three network layers- Open Flow virtual switches, Open Flow controllers, Open Flow application. Open flow controller is used to maintaining the Open Flow protocol communication channels. It also maintains local state graph to exposes northbound API to Open Flow software applications. Open Flow architecture facilitates innovation in network. SDN uses open flow architecture for providing network virtualisation.
Open Flow is a type of programmable network protocol for Software Defined Network (SDN) environment that is used for communication between controllers and Open Flow switches. Open Flow separates the programing of network device from hardware, and provides a standardised way to deliver a centralise, programmable network, which can quickly adapt to change network requirements. An Open Flow switch is an allowed Open Flow, communicates over Open Flow channel to an external controller.