For data flow traffic in an IoTSP system, for example, a gateway is provided with data flow rules, one or more of the data flow rules being a receiving rule defining at least what incoming data will be accepted and one or more of the data flow rules being a publishing rule defining at least what data to send to one or more other computing devices acting as gateways in the system. The one or more receiving rules are applied to incoming data, and the one or more publishing rules to stored and processed data to cause sending one or more pieces of the data in response to a condition in a publishing rule being fulfilled.