I have a printer that accepts socket connections and is connected by wi-fi to my router. I have a cloud app server I want to communicate with it.

The printer has an internal/LAN IP address on my home network 168.192.0.6 (say).

My router has it’s own WAN IP on the internet – provided by my ISP – say 1.1.1.1.

Do I need to use port forwarding on the router to allow traffic originating from the net to ‘find’ the printer?

eg: the app server sends traffic to 1.1.1.1:3128 and the router works out that this is 192.168.0.6

Any other alternatives?

(I realise if my isp doesn’t allocate static IP’s this is onyl a temporary solution but I just want to prove it works for now, it’s not a long term thing)

To go through your router you need to set up port maps:

External IP: External Port -> Internal IP: Internal Port

So if your webcam was 10.0.0.1 on port 80 (http), you might map

1.2.3.4:8001 -> 10.0.0.1:80

So to see your home webcam from work you’d stick 1.2.3.4:8001 into a web browser assuming 1.2.3.4 was your external IP.