I thought your bt voyager 205 supported UPnP but I'm not sure.

If you want to manually forward a port, then follow the instructions here (must set up a static ip 1st for it to work!!!) & open port 6346.
http://www.portforward.com/btvoyager/205adsl.htm If you do this, don't forget to use the manual port forward setting within LW.

Disable your XP firewall! (go to the control panel, double click on Windoze Firewall, check the disable box) & instead just use Norton FW but you need to configure it: *Configuring Norton Internet Security