Fault-tolerant Ethernet middleware for IP-based process control networks

We present an efficient middleware-based fault-tolerant Ethernet (FTE) developed for process control networks. Our approach is unique and practical in the sense that it requires no change to commercial off-the-shelf hardware (switch, hub, Ethernet physical link, and network interface card) and software (commercial Ethernet NIC card driver and standard protocol such as TCP/IP) yet it is transparent to IP-based applications. The FTE performs failure detection and recovery for handling multiple points of network faults and supports communications with non-FTE-capable devices. Our experimentation shows that FTE performs efficiently, achieving less than 1-ms end-to-end swap time and less than 2-sec failover time, regardless of the concurrent application and system loads. In this paper, we describe the FTE architecture, the challenging technical issues addressed, our performance evaluation results, and the lessons learned in design and development of such an open-network-based fault-tolerant network.