Is It Not Need to Port Forwarding When Creating Payload , if I Use 3g Dongle ?

hello friends, i found a article when i search google about "port forwarding using dongle" ,

the article is :

"With a 3G dongle you will connect directly to the provider's mobile network, which implies you have no direct control over the ports.

But there's really no need to, because you will get assigned a single IP address, where no port forwarding is needed - you have only one device behind the IP, as there's not router present. Port forwarding is not needed, as the device's IP address corresponds with the external IP address assigned to you by the mobile service provider.

So in short, the physical device connected through 3G is assigned to with a dedicated IP address, so no port forwarding is even needed. There is just one question though: what ports does the service provider allow you to choose? Keeping in mind they don't like heavy trafficking, certain ports (in)famous for exactly such are probably blocked for use."

now i want to know,

1) is that actually correct ?

2) if it correct how to do this ?

3) how to find the ports does the service provider allow us to choose?

please help me guys................................................