Hi I have a remote router with public IP and a device (not a PC) on the lan of the router with private IP 192.168.1.3.
The device has embedded web server so I set up a port forward rule in the router and can reach the devices configuration pages on port 80 using from browser. That all works fine. There is a real time activity log option this is using Java.
In the LAN enviroment ie my laptop connected directly to device ..I click the activity log option and a small file is downloaded to my PC here’s part of it opened in notepad.

<?xml version="1.0" encoding="UTF-8"?>
<!-- href attribute contains relative path;
     codebase attribute not specified -->
 <jnlp spec="6.0+" 
codebase="http://192.168.1.3"
     href="jnlp/LogViewer.jnlp">
     <information>
    <title>Activity Log Viewer</title>

When I execute this file the application loads and I can log in.
When I do the same on the remote router It downloads this file to my laptop but it does not launch and java times out with connection error. I did try changing the lan address(192.168.1.3 in this .jnlp to the public IP of the remote router but it does not connect.
When testing this on the LAN I ran wireshark and it always use port 80 on the device but yet does not work remotely even though port 80 is forwarded.
What must I do in the router to allow this to work?
Thank you.