Internet Help-Changing NAT type?

[Wana_make_a_guitar]

While playing online game with my optus 3G wireless modem, i've noticed that I have had trouble connecting to some games and playing co-op with other people or just simply talking to other players. Apparently there's this thing called NAT type which determines how much you're allowed to interact with other players and connect to certain games and my NAT type is set at moderate according to my Xbox 360 (the console I usually play online with)
The specific 3G modem I'm using is a Huawei E583C using an optus sim card. I've called technical support at optus and they've told me that the modem itself doesn't actually have the technology to change the NAT type by itself and you have to use the advanced setting to manually change the NAT type.
I actually have no freaking idea how to do this and was wondering if anyone could give me a hand if you can, as it's getting slightly annoying that I can't even have two matches with my friend in a party on Xbox Live.

 

[ByteFrenzy]

NAT is short for Network Address Translation. Your Xbox has an address on the network that contains it an your 3G modem, you should be able to display it some where in the setup menu. The address is four groups of numbers separated by three periods. Probabbly it looks something like 192.168.1.2 . The problem is that you can't use this addres when you go out on the internet. Your 3G modem translates it into a different address which is permitted (hence NAT). Most 'nice' internet applications like http (web) and POP3 (mail) will reply in a way that allows the 3G modem to just do the NAT in reverse so that the data arrives at he correct device, your Xbox. A lot of games behave in a not-so-nice way and the reverse NAT doesn't work. Waht you have to do is set up an exception list in your 3G modem where you tell it that traffic coming from the internet with a specifc 'port' (which is a number identifying the type of data such as 80 for http) has to be forwarded to a specific device (which is why these settings are often called port forwarding). You need to know the port number on which traffinc for your Xbox is arriving (try google 'xbox live ip port' and read the message on Microsoft support) and the address is the one you found in the settings of your Xbox.

 

[Wana_make_a_guitar]

I've tried port forwarding, but for this modem, it is just impossible. I tell it what ports I want open and whatnot and select the propper settings for them and then click apply and nothing happens. I've also tried the DMZ settings, nothing, and UPnP settings. Still nothing.