ntl will not usually provide more than one broadband connection to a property. You can however, use a broadband router to connect additional computers to your existing connection. See
http://www.gyre.co.uk/help/broadband...on_sharing.php for more information.
Since you will be going outside, a wireless router would be required as you should not run standard network cable outside. Also, be careful not to buy an ADSL router, as these will not work with ntl.