Composing Heterogeneous SDN Controllers with Flowbricks

The software-defined networking (SDN) paradigm allows network operators to conveniently deploy network services through a centralized controller. Recent interest in SDNs has fueled the implementation of a variety of network services on controllers written in different languages and supported by different organizations. Given the large number of network services and their increasing complexity, no single controller can provide all network services. Even if a controller provides all the desired services, it is unlikely to have the best-in-class implementation of all those services. To address this problem, we propose a framework for composing a control plane using controllers from different vendors. The framework applies services implemented on heterogeneous controllers to the same network traffic. Allowing network operators to deploy services implemented on heterogeneous controllers prevents vendor lock-in at the control plane. Furthermore, network operators can quickly deploy a new service by integrating a controller (possibly supplied by a different vendor) into the framework. Our framework is designed to operate in a way that is transparent to the controllers and does not require additional standardization.