If you are having trouble with UPnP or port forwarding issue, you need to assign a static IP to your device as the following steps:
• Tap on the "Settings" icon on your iOS device screen.
• Go to the "Wi-Fi" tab at the top of the "Settings" window.
• Move the slider at the top of screen to the "On" position if Wi-Fi is not on already.
• Tap on the little blue arrow next to your Wi-Fi network name in Photo 1.
• Tap on the "Static" tab in the window.
• Make them (IP Address, Subnet Mask, Router, DNS etc.) all the same as your current network settings in DHCP tab of Photo 2.
• Now your iPhone has a static IP address. You need to setup your router to forward a port (37101 as shown in Photo 3) to the static IP outside local notwork.
• The router is the device that the Internet sees; it holds the public IPaddress. The devices behind the router, on the other hand, are invisible to the Internet as they hold a local IP address each. Port forwarding is necessary in the router because the devices will send information directed to the public IP address and the router needs to know where to send that information.
• The local IP address of your iPhone should be automatically shown like Photo 3 to you once the app installed and started. If your iPhone is behind a router, the router will need to setup your router to allow incoming traffic by mapping the public IP address into the local IP address through the port forwarding technique. For more information on port forwarding and router configuration, please see www.portforward.com/guides.htm
• For security reasons, routers don't normally allow external traffic into your home or office network.
• Some ISPs can block incoming connections to well known ports (80 and 8080 for HTTP, 20 and 21 for FTP, 25 for SMTP, 110 for POP3). If that is the case, you need to forward a non blocked port number in the router and map it into the "Forwarded Port" as shown in Photo 3.