On-the-fly Table Insertions on Programmable Software Data Planes

Novel applications require a robust and reliable connection to provide the services for next-generation networks. The complex nature of these algorithms needs fast and efficient stateful processing. Using Software-defined Networking (SDN), new algorithms can be implemented into the network in a platform-independent way. The upcoming Portable NIC Architecture (PNA) for P4, a language to program data planes in SDN, allows inserting new table entries without controller interaction. Thus, it unleashes more performant and stateful applications without the overhead of the controller. We implement and evaluate these so-called ‘add-on-miss’ insertions introduced by the PNA for a P4 software target. In addition, we discuss the influence of latency and throughput optimizations on software packet processing systems. We determine the impact of these optimization strategies and which performance properties and costs can be measured with each. In our analysis, we model the costs of insertions based on an extensive baseline and compare them to table entry lookups and updates. We analyze the influence of the frequency of insertions and multi-core scenarios. Finally, we demonstrate that the approach scales for realistic scenarios.

I. Introduction

The upcoming 6G standard for communication networks will enable novel and complex applications, ensuring an ultralow end-to-end latency as well as an ultra-low packet loss rate. Connections with these properties are essential for critical applications in domains such as transport, industry, and medicine. Optimized reliability methods are necessary to achieve these goals. An example of such an approach is hybrid automatic repeat request (HARQ). This algorithm increases the reliability of connections using forward error correction and repetition of non-acknowledged packets. Such complex algorithms must be distributed across different components in a network, either to the network interface card (NIC) or entirely to middleboxes to deal with demanding network applications.