You will have to forward the IP address of the system into your router. Connect to the Administration area of your router, then go to the Port Forwarding and add the local IP address of the system and its PORTS. You will have to check the manual to see what are the ports for the application. Fill the ports and the IP address, and then connect to another network and you should be able to see the live stream. If your router supports DDNS, create an account on one of the supported services. The next time you connect, input the subdomain from the DDNS service. This is to avoid typing IP addresses in case you have a dynamic IP for your router.
In iPOLiS Device Manager, type the same address given by the DDNS service and it should work. I am currently doing this for a remote location where surveillance system is installed. The cameras aren't from the same manufacturer, but the principle is the same.