What is Port Forwarding?
Port fowarding is telling your router what ports to open to the surface world (connections surface of your local network) and where to direct traffic that hits those ports.
Belkin Wireless Router Reset
Some software requires clear ports to be open on your router so that they can function properly. Some Peer-2-Peer software requires ports to be open for communication to occur between online servers, etc. If you plan to stream media from your home Pc to your iPhone or mobile device, odds are you will need to open a port for that communication to happen.
When you have a gadget related to your router/network, it will have a local Ip address. For example 192.168.1.10. Let's say you have two computers related to your network, a laptop and a desktop. The desktop holds a lot of your media files that you want to stream to your iPhone app with a server/iPhone app called ServeToMe and StreamToMe. That media server running on your computer will want to communicate over a port, let's say port 5584.
What you will want to do is First set your desktop engine to have a Static Ip address so it's all the time the same. Let's give it the address of 192.168.1.150. Then we will log into our router and go to the port forward section settings section. Add a new forward called Media Server, set the port value of 5584. If they give you a from and to field, put 5584 for both. Then select the protocol, it will either be Udp or Tcp, or both. You can just select both for this example. Then the last thing it will ask is the target Ip address. Enter your desktop Ip address of 192.168.1.150. Save the settings and you are done!
Now your iPhone app can communicate from your 3G network through the internet to your router and then through to your Pc. That's what port forwarding does. If you didn't set up this port forward, the iPhone app would get to your router and then your router would block the traffic because there was no rule setup.
One thing to note about the iPhone app and the address you give to it. You will Not give it the 192.168.1.150 Ip address, as this is your local Ip address and only within your local network. You need to give the iPhone app your Global Ip address which is the Ip address on your router. I have a good explanation on how to setup your global Ip address with a domain name service.
Written by Josh R Bellendir, 2/27/2011
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