O-MI/O-DF vs. MQTT: A performance analysis

Over the past decade, a flourishing number of concepts and architectural shifts appeared such as Industrial Internet of Things (IIoT), Industrial CPS or even Industry 4.0. Unfortunately, today's IoT as well as Industry 4.0 environments, look more like a collection of isolated “Intranets of Things”, also referred to as “vertical silos”, rather than a federated infrastructure. Breaking down these silos is a key challenge in both the IoT and Industry 4.0 communities. This paper is intended to present and discuss two open and standardised messaging protocols designed for IoT applications, namely: MQTT and O-MI/O-DF. First, a traffic load's analytical model derived from the MQTT standard specifications is presented. Second, a comparison study between MQTT and O-MI/O-DF standards is carried out based on a real-life industrial implementation. This study brings a deep understanding of the extent to which these protocols are performant (from a traffic load perspective) and how they can impact on future architectural designs.