Hostnames and ports for firewall configuration

We have a number of Android-based clients running on a network with very strict firewall configuration. For every external service that we need to connect to from inside this network, we need an explicit firewall configuration.

I’m trying to find the hostname(s) and port(s) that we need to open outgoing traffic towards. I haven’t been able to find these in the current documentation on in this forum.

Thanks,
Erik