A TDMA Ethernet Switch for Dynamic Real-Time Communication

A real-time communication medium must provide a special coordination mechanism to guarantee bounded communication delays. Implementing this mechanism in software offers flexibility but reduces reliability and performance. On the other hand, customized hardware solutions deliver high throughput and predictability, but they increase the implementation cost and are unable to adapt to the specific needs of individual applications. In this work, we introduce a switch that implements a programmable dedicated time-triggered packet switching mechanism on top of Ethernet. The switch, called the Network Code Switch bases on the NetFPGA system and executes flexible but verifiable state-based schedules encoded in the Network Code programming language. This permits the user to tailor the communication behavior to the needs of the distributed application with verifiable performance. We discuss our experience starting at the designing to the implementation of the prototype, and describe how we exploited modularity and code reutilization to reduce the implementation costs and increase the flexibility of the architecture. We also validate our design by evaluating the overhead and throughput of the implemented prototype.