What's the problem?
Following on from this thread, I thought I'd post up some detailed info about an issue that may affect people.
If you're having problems chatting through Xbox Live or joining in online games, then it's most likely that you, the people trying to connect to you or both, are having a problem with the NAT (Network Address Translation) on the router.
To identify if this is the problem, go to your Xbox Dashboard, then to the System page>Network Settings>Test Xbox Live Connection. It will then run through a serious of tests. Assuming it passes them all, note what it says next to NAT. If it says Open then you're fine, therefore it could well be your mates settings that need addressed, so read on so you know what to tell them they have to do. If it says Moderate or Strict then you want to address that as it will be giving you potential problems when connecting with other people - all dependent on their NAT settings too. To explain.......
Will things work okay?
So as you see it's only usually if an Xbox with a Moderate or Strict setting tries to communicate with one with is also Moderate or Strict that you'll have the issues - but it's best if both parties are Open, then definitely no issues.
How do you fix it?
You need to do this on your router.
With each router being different, I can't give details for all, but you basically have to get to the setting where you can Open Ports for an individual device, the device being identified by it's IP address. The ports will have been closed on some routers by default for security reasons. Go to Network Settings>Edit Settings to see what IP address the Xbox has.
Once you're in that setting, you need to open up the following ports.....
UDP - 88, 1900, 3074 and 10280
TCP - 2869 and 10243
Here's what my router screen looks like for this....
Once you've done that you should be fine. I think you may have to restart the Xbox. You can then do the Xbox Live test again and hopefully it will now show Open against NAT.
The above menu configurations were in respect to an Xbox 360, but the original Xbox has them as well, just in a different layout and the NAT issue will affect them as well. From memory, on the Xbox it also shows the Open, Moderate or Strict setting on the original Xbox too.
So, if you're having an issue joining in online games or talking to mates, then this is likely to be the issue - either with your settings, your mates or both.
I had this issue when I had my first Xbox, trying to join online games and then dropping out etc. - took a fair bit of searching on the support to finally discover about the NAT thing. MS don't exactly make it easy to find, and then I had to dig deeper to find which ports to open as on one of the support pages the solution thay gave was to get a new router - one that was Xbox Live compatible!!!! Good ol' MS! lol