- Devices poll the server every few seconds
- Server returns playlists (i.e., URL/duration tuples) that clients iterate through
- Special "alert" playlists can be "pushed" to devices to playback with higher priority than current assets
Time. Also, for a number of reasons (including historical ones) HTTP polling has been the preferred mechanism to do this. In the future, however, I would love to have the time to reimplement signalling atop MQTT.