if your NAT is open and ur already lookin cool then u have the same problem as i do ur internet is not fast enough and even if you do miraculously force yourself to be host then the players in that match will lagg like hell and end up backing out anyway hope it helps
EDIT Response: well ok reset your router, then port forward if that dosent work than call the router company. If you are using just a modem just call the company and you should be cool ALSO VERY IMPORTANT SET UP A STATIC IP it worked for me.