A Fault Tolerant Software Defined Networking Architecture for Integrated Modular Avionics

The next generation aircrafts rely on the Integrated Modular Avionics (IMA) concept with the objective to fulfill the challenging requirements through enabling dynamic resource sharing among the avionics systems. Deterministic Networking (DetNet) is a key technology to provide transmission of time sensitive digital information among IMA sub-systems by obeying their strict timing requirements. As an important feature, DetNet should have a reconfiguration capability to retain the deterministic communication among interconnected systems in case of network failures. In traditional DetNet solutions, the communication reliability between two end systems is maintained by transmitting duplicate data frames over two disjoint paths, one of which will be discarded by the destination end system. This redundant architecture ensures the seamless delivery of data frames even if one of the redundant paths becomes disconnected; however, a subsequent failure on the remaining path breaks down the communication between the corresponding end systems. The centralized architecture of Software Defined Networking (SDN) paradigm simplifies the reconfiguration of the network infrastructure with respect to time varying network conditions and communication needs. The SDN technology can be an effective tool to achieve the determinism objectives of next generation IMA based avionics networks thanks to its reconfiguration capability and the built-in traffic policing mechanism provided in its recent versions. In this paper, we propose an SDN based architecture for fast failure protection in next generation avionics communication networks. The proposed architecture combines SDN and Loop Free Alternates (LFA) technologies to significantly enhance the existing redundancy based failure management techniques by dynamically replacing whichever of the redundant paths fails with an alternative one. This is a major enhancement since the communication will continue even if there are multiple subsequent failures in the network. LFA is an IP Fast Reroute (IPFRR) mechanism which was standardized by IETF to provide a fast loop-free convergence after a network failure by rerouting the disrupted traffic to pre-configured alternate paths. Our approach computes two redundant paths to transfer a data flow between two end systems, and relies on the LFA technology to protect each link on these redundant paths against network failures. The preliminary experimental results demonstrate that the proposed approach yields considerably lower failure recovery times to maintain the redundancy among communication paths. We will also present a video streaming demonstration using COTS computers and two FPGA development platforms to facilitate the discussion about how the proposed SDN-based DetNet technology can be implemented on top of this infrastructure.