Sometimes, you can not do what you need to with either port forwarding or port triggering. For instance: Let's say you want to host multiple games on multiple computers inside your network. Or, perhaps you want to have multiple Xbox 360s running at the same time. The bottom line is that you have multiple devices on your network who want to use the same ports. And unfortunately, you can only port forward the necessary ports to one of those nodes because you can only forward a given port to one IP address in your local network. In other words, one port per IP address. Since you can not port forward the same port to multiple devices on your network, even in a best case scenario, using port forwarding, at least one of the computers or Xbox 360s will be left with blocked ports, or a Strict NAT.
There are four major problems that you may run into that would require alternatives to port forwarding.
For each problem is a recommended solution. Granted, the solutions for problems like this are not always free.
The first step is to purchase a VPN service such as AirVPN. To use a VPN, you will need to install a VPN Client. You may either use AirVPN's client, or the OpenVPN Client. The next step is to log in to AirVPN's website, and from there you can tell them which ports you would like forwarded to your computer. It is important to note that when you connect to a VPN using AirVPN and your VPN client, you will receive a new external IP address.
Once you've activated an account with AirVPN, you can easily forward ports using their web site.
First log in to your account at AirVPN.org
Next, Click the Member Area section of the navigation bar near the top right corner of the AirVPN web site.
From that drop down menu select Forwarded ports.
Finally enter the port number that you wish to forward, select the protocol for which you would like to forward the port, specify your local port, and click the Add button.
You are done! piece of cake right? For more information on which ports to forward for a specific application please see our database of common TCP and UDP ports where you can find the TCP and UDP ports for virtually any application.