COD4 Online problem

[Sonicboy 101]

Hi all, trouble here. The online in COD4 has an annoying issue. When I try to invite someone into a game, or when I get invited, a message comes up saying "unable to join". This isn't a random error since I get it most of the time (I've only had one success so far). What's the problem, and is there a way to fix?
Thanks in advance.

[cal360]

Well your NAT could be moderate or Strict which could be causing a problem, you've got a bad connection or the host has got the problems I just listed. I'm not too surprised if it's lately though Xbox Live has been haywire.

[Sonicboy 101]

Well your NAT could be moderate or Strict which could be causing a problem, you've got a bad connection or the host has got the problems I just listed.

Doubt it, when I choose to try playing a game from lobby it works fine.
It seems weird, I can play people from the UK fine but when I try to invite from US or anywhere else it fails to do so?

[cal360]

Sounds like a connection problem, the connection is probably too weak for both sides to connect properly because of the distance. It may be that Call of Duty needs a very tight connection to play. I've had problems with COD 4 similar to yours, but after sorting out my NAT I haven't had too many problems. I only have this problem with one friend who seems to have a bad connection.

[Triv1um]

CoD-4 is very unreliable from time to time.

I've had this problem before (not just overseas, just in general). The next day its fine.

[bigg146]

On COD4 in doesnt let me invite some of my friends to a game and i cant join theirs either i cant even talk to them in games any advice