Software-based Internet Protocol offload engine for low-end field devices

Internet Protocol (IP) technology can be employed in field networks for process automation. However, low-end CPUs, which are generally used for operating field devices, require excessive computational power for processing IP and its security protocols such as IPsec. We propose a software-based protocol offload engine (POE) approach, by which only the bottleneck in IP stacks is implemented as hardware and the rest is implemented as software on an alternative CPU. The experimental result shows that the software-based POE achieves the IP and IPsec performance required for use in field devices with a macrocycle of a few hundred milliseconds. The software-based POE also eliminates the overhead of the key exchange protocol processing from a host CPU.