Acceleration of MQTT-SN protocol using P4

MQTT-SN is one of the protocols attracting attention for Internet of Things (IoT) systems. It is suitable for collecting data from sensor devices due to its lightweight protocol design and loose coupling nature derived from the publish/subscribe model. To handle enormous IoT data, the performance of MQTT-SN brokers is a significant concern. Typical approaches to improving performance are using multiple brokers for load distribution and bringing out the hardware performance. However, the former involves larger latency due to cooperation overhead among brokers, and the latter has less flexibility than generic software brokers. To address these problems, we propose PAMS, an in-network acceleration method of the MQTT-SN protocol. PAMS makes a network switch perform a part of broker functionality by using P4, a leading data plane programming language. Although PAMS introduces in-network acceleration for performance improvement, it uses a software broker for the principal functionality of MQTT-SN so that we obtain flexibility as well. From analytical and quantitative evaluation, we clarify that PAMS lowers the load of the broker and reduces latency.