Hybrid Control Model for Flow-Based Networks

This paper shows our design of a hybrid control model for flow-based Software Defined Networks (SDN). There are many research efforts related to the flow-based networks, however, our work was inspired by OpenFlow [1] technology. OpenFlow is a promising future Internet enabling technology, specially that it was counted as a key enabler technology for SDN as explained in [2]. And thus, it has a great potential to improve the current Internet by providing new functionalities and a new control scheme and thus enabling new smarter applications to be created. However, there have been some debates regarding the scalability of the OpenFlow´s controller, this is due to the design of OpenFlow as it depends on a centralized controller to control flows. Our study aims to provide flow-based networks with a hybrid control model that combines both central control and distributed control, in order to provide a more relaxed control and to provide a fail-safe-like mechanism for such networks. This is done by designing two new features, network equipment to equipment flow installation, and a new type of proactive flows. Through which we aim to relieve some of the load off the central controller, make flow-based networks more self-aware, and provide a method to support flows with strict timing requirements. This hybrid control model is proposed as a step forward towards encouraging a wider adoption of flow-based SDNs as an easily programmed network that holds a great potential as a future Internet technology.