Hello,
If you are having trouble hosting a online game, try the following steps.
-Check and make sure the ports are actually open as needed. You can do so at the following site,
Click here-If the ports are open correctly, try disabling any firewalls or anti virus program you have installed on your computer, router or gaming device.
-If this still is not working, and you have intermittent internet connections issues (like browing a site and your lose internet) outside of the game, you may have a bad internet connection, router, modem, cables or Network card on your gaming device. Your internet connection could be experiencing real bad latency, which you will need to contact your ISP.
Alternatively, you can contact technical support at Eidos Interactive as they can provide additional support.
Regards,
G33k