[Rldm840]

A quick comment based on our experience. We have been providing a proprietary messaging server based on WebSockets and HTTP Streaming for many years now, mainly used for financial trading, online betting, and aerospace. The increased popularity of MQTT in recent years pushed us to find some good points of contact between MQTT and our well established practices to deliver real-time data through the Internet. Simply tunneling MQTT over WebSocket didn't seem to be enough in some scenarios (perhaps corner cases, perhaps not, we don't know yet). In particular, what is completely lacking in MQTT (and in MQTT over WebSockets) is the ability to throttle and resample the data on the fly based on the available bandwidth. To make a long story short, we decided to "add" this and other features to MQTT by creating a gateway that transparently remaps MQTT over our proprietary but open protocol (TLCP). The result is a solution that exposes very standard MQTT API (Mosquitto-like), but is much more Internet-friendly than MQTT over WebSockets (both for throttling and other reasons, which I don't list here to keep it short).

In this Dzone article we explain a bit more about adaptive throttling: https://dzone.com/articles/mqtt-throttling-data