"Failed to join game" in tcp/ip game

[Etos]

Hi all,

i'm trying to play tcp/ip game with a friend
and it doesn't matter who is the host,most of the time we get the error "failed to join game"
(not all the time,sometimes the game crahes)
is this related to an unopened ports?
if so,then what is the number of the port we should open?
we both play version 765...

[ChaosEmpire]

7601 is the most recent port you need to host a game