Loopback Strategy for TSN-compliant Traffic Queueing and Shaping in Automotive Gateways

In this work, authors present a Hardware (HW) based loopback strategy which is a new paradigm in network processing, for HW efficient and cost-effective integration of Time Sensitive Networking (TSN) functionalities within automotive Gateways (GWs). This innovative HW architecture permits to manage the complexity of TSN functionalities integration within In-Vehicle Networks (IVNs) by reusing the already existing HW resources in GWs, interconnected in such a way that allows to perform all the required processing, independently of the TSN algorithms in place. The proposed architecture follows the Software Defined Networking (SDN) approach, separating control plane and data plane. The data plane is kept as simple as possible to maximize performance and reduce latency, while the complexity of the different TSN algorithms integration is handled within the control plane. Furthermore, it provides fully autonomous management of the TSN algorithms in HW, without intervention of the CPU. The newly introduced loopback path provides the capability to send frames from the egress stage back to the processing stage, to be processed again when required, allowing also to replicate them and independently route them wherever needed by the application. The loopback is also scalable, flexible and modular allowing to interconnect as many loopbacks as required by the network device. It also allows to process frames from the loopback path in parallel with frames coming from ingress ports, having thus no negative impact in the throughput of the network device. Moreover, it has a strong focus in low latency, securing a fast track for the loopback path which allows to keep the device performance under control, contributing towards future automotive TSN-compliant networking solutions.