Is there an overview showing the communications between teslaMate, MQTT, Grafana, Postgress and the car

[markuswells]

I am trying to figure out why I get no data in Grafana. I have tried several things, but I really need a Work flow diagram or discussion explaining how ALL the communication works between all the partners.
Not details, just overview, like:
TeslaMate makes API call to ...
Response is handled and forwarded to...

I suspect my issue is that the car can not reach inside my network.

Thanks
Markus