Thingsboard Integration with Chirpstack

I will really appreciate if someone can tell me how chirpstack application server is pushing data to thingsboard cloud console?

I am configuring thingsboard server address and access key in variables field at chirpstack console.
And I am selecting chirpstack as integration type on thingboard.

I want to know how things are working under the hood ? Which protocol is used to push data, whether its MQTT or HTTP?

what is payload encoding format(JSON, Protobuf etc)? what extra metadata(RSSI, SNR etc) is being sent alongwith payload?

Following version of chirpstack are in use :


Please see for which information is forwarded to Thingsboard.

The ChirpStack Application Server > Thingsboard integration is using HTTP.