Host Bypassing: Direct Data Piping from the Network to the Hardware Accelerator

Computer networks have become very important and influential over the last years for many common services such as Internet connectivity as well as time-sensitive applications such as videotelephony. Furthermore, approaches like in-network computing enable the offloading of latency-critical and high-performance network functions into the network, e.g. 5G network functions, to enable such time-sensitive applications. In this work, we show how FPGAs in PCIe-based systems, which are typically used as hardware accelerators for latency-critical in-network functions, can be integrated into the data path. Our approach, named host bypassing, allows direct data transfer from the network interface to the accelerator and accomplishes substantial performance benefits over existing state-of-the-art approaches. Our detailed evaluation results demonstrate the possibility of achieving deterministic low latency while operating under heavy load without any packet loss. In addition, fewer CPU resources are required.