Cloud Differences¶
This document records key differences between the reference AWS implementation and other Cloud Providers IoT implementation:
Google Cloud Platform (GCP)¶
Authentication¶
Devices connect to the broker host using TLS 1.2, but authenticate against MQTT using a username (any) and a JWT token, which has been signed with the device key. Which means devices need to be provisioned with the TLS Root Certitifcates AND the device-specific keypair.
Digital Twin¶
GCP has Configuration (AWS: desired) and State (AWS: reported).
Devices receive their configuration by subscribing to the /devices/${deviceId}/config topic.
On successfull subscription they will receive their configuration on this topic.
If the configuration is changed, the updated config will be published to the topic.
There is no delta.
Devices publish their state to /devices/${deviceId}/state topic.
They always must publish the entire state, there is no native support for partial update
Websockets¶
The IoT Core does not support Websocket connections which is used in the app to get notified in real-time about changes on device state.