You will have to have opened up the ports 6881 to 6889 on your router and firewall software to start with. If that doesn't noticeably increase the speed of your downloads then I'd suggest choosing a higher port number picked at random as your ISP will possibly have restricted transfer rates on those ports. You only need one port - just that as standard torrent software uses a range of ports.

To change the router settings go to a section titled 'advanced routing/gaming options' or similar. As said above, best off googling for help with your router and firewall settings.

Cheers,

Andy