Reusability of Software-Defined Networking Applications: A Runtime, Multi-Controller Approach

The Software-Defined Networking (SDN) ecosystem is still characterized by a multitude of different controller platforms, each with its own programming model, execution model, and capabilities. This creates a danger of a controller lock-in for both developers of SDN control applications and operators of SDN networks. Since no single controller platform appears to dominate the ecosystem for the foreseeable future, there is a need for portability of control applications between different platforms. We propose an architecture based on executing multiple instances of different controller platforms concurrently in a network to provide the SDN code the environment it was written for. It is built around a controller-independent network event routing element called Network Engine that provides composition and conflict resolution. Results obtained in realistic scenarios demonstrate the feasibility of the proposed approach, which increases both developer productivity and operational flexibility. A preliminary prototype of the architecture is available for testing as an open source project.