I have a big doubt that I'm not able to solve.
Basically, I want to understand how the smart device that I have in my home communicate with their servers, or better, how their servers can call its and sending commands (like turn on/off) without any type of port forwarding.
I know that if I wont to access to a device remotely I need to expose it on the network through a port forwarding on my router, but, I didn't configured anything for these devices, so, what kind of method they use?
Could someone let me know?