IP Addresses

Dear Friends,

I have a lot of Yeelight, combined with Xiaomi Smart Home products at home and they are working perfectly. This is at home where the connections to Xiaomi/Yeelight cloud servers are allowed.

Now I am setting up 20 Yeelight 650’s in the Office. I am getting stuck to allow it through the firewall.
All connections are standard blocked. We need to specifically define rules if a new server/device need to communicate with the outside (Internet).
Is anyone able to tell me how Xiaomi/Yeelight talks to the outside world?
What is the IP address and Port number where the communication goes through?
The devices will be set to region China so it will communicate to the Xiaomi cloud server in China.
When using Yeelight App, is the same server/ip/port being used as Xiaomi MiHome App?

Thanks in advance.

Kind regards,