Port Forwarding to get to a computer on my LAN from Internet Alternative Method

Question

I am planning a project based on the concept of  IoT but there's a problem. I can't really install a Raspberry Pi on a LAN. It's accessible through the Internet, without making port forwarding, or Hamachi, or NGROK. The idea is to create a product that works "Out of the box".

Can anybody help me out?

Answer 1

Try looking into UPnP. 

There must be a way for your device to tell your home router that it provides some service. Your router will set up port forwarding automatically(if it supports UPnP that is).