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.