Gateways are distinct from routers or switches in that they communicate using more than one protocol to connect multiple networks[1][2] and can operate at any of the seven layers of the OSI model.
Project HERMES, run by the Ecuadorian Civilian Space Agency, was first to implement this kind of gateway on June 6, 2009.
[15][16] To achieve sustainable interoperability in the Internet of things ecosystem,[17][18] two dominant architectures for data exchange protocols are used: bus-based (DDS, REST, XMPP) and broker-based (AMQP, CoAP, MQTT, JMI).
Protocols that support information exchange between interoperable domains are classified as message-centric (AMQP, MQTT, JMS, REST) or data-centric (DDS, CoAP, XMPP).
[19][20] Interconnected devices communicate using lightweight protocols that don't require extensive CPU resources.