I have a fairly complex router full of options that im not even sure what most do. Its a Sonicwall TZ170. So far I have forwarded ports 6100-6200 +6073 UDP. I have allowed multicasting as I think I read a mention of this in one of frogboy's guides.
From here I am able to get into game lobbies quickly connect to 2-3 people and from this point its just a mess off attempting to connect to the other 2-4 people (as in... it never actually connects to them). This is usually followed by some failed NAT connection error message or you've been kicked from the lobby message (after 5-10min of attempting to connect).
I know that some option in the router must be the problem because when I connect through DMZ there is no problems its lightning fast (i joined a lobby with 9 people in it and was connected to everyone in under 5 seconds). On a side note I have also redirected all Pings to my computer (in case it was some problem with pings) and this did not worsen or improve the situation at all.
Thanks for any input.
Bart.