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Welcome to the preview of DPS for IoT

Distributed Publish Subscribe for the Internet of Things is a new protocol that implements the pub/sub (publish/subscribe) communication pattern. The pub/sub pattern for device to device communication is simple and powerful. There are several existing pub/sub protocols that are seeing heavy use in IoT application most notably MQTT and DDS. Two characteristics of pub/sub that make it attractive for IoT uses cases are support for loose-coupling between publishers and subscribers, and inherent support for point-to-multipoint messaging. There are generally two implementation approaches: brokered (MQTT) or multicast (DDS). In brokered pub/sub systems publishers and subscribers connect to a centralized server that routes publications to matching subscribers. In a multicast pub/sub system subscribers receive messages from all publishers and selectively forward matching publications up to the application. The disadvantage of a brokered approach is that the broker is single point of failure, must be 100% available, and scales linearly with bandwidth and processing capability of the broker. Also all messages do a round-trip through the broker which puts a lower bound on communication latency. Multicast pub/sub systems are hard to scale beyond a single subnet and work much better over wired than wireless networks.