There are two ways by which IoT devices can be on-boarded.
Agent Access
This involves vEPSA (vitalpointz Edge Service Platform Agent) software or SDK needs to be installed or implemented in the Device Code. This method is highly recommended as the Agent automates fetching of device certificate, device id and device whitelisted-topic.
Agent-less Devices Access
In a scenario where the device code cannot be integrated with vESPA, this method is useful.
When a device is registered, device topic may be configured to whitelist. Once whitelisted, the device can send MQTT messages using the whitelisted topic (without the certificate).