Connection problem

Hello,
i have one problem
when ever i join into any room in game ranger(game site) it tells the


"your internet connection is behind a "port ristrected cone NAT Router" that prevent you from connecting to some palyers in peer-peer games"

after that i click on continue i join into the room


but in just 2-3 minutes it will come out from from the room and some time the game ranger also frequently disconnected and connected...........



please any one can tell how to fix this problem.......
plzzzzzzzzzzzzzzzz