Enhanced robustness of control network for Chinese Train Control System Level-3 (CTCS-3) facilitated by software-defined networking architecture

In order to provide high reliability for train control networks, ring redundant network configuration has been widely deployed in Chinese Train Control System Level-3. In this paper, we propose a centralized ring redundant link failure failover management scheme that is based on a software-defined networking architecture, where OpenFlow protocols and a POX controller are adopted. Contrary to the traditional ring redundant schemes that flush all the forwarding information databases when failover proceeds, the proposed scheme simply updates the forwarding information needed to be changed according to the global topology and is link-flapping-free. Simulation and experiment results demonstrate that the proposed scheme is superior to the Media Redundancy Protocol in terms of the obtained system recovery time, the bandwidth, the time delay and the packet loss when failover proceeds.