Telewest "Cable" requires a stand-alone router that connects to the supplied cable modem by ethernet.
If the router you are looking at is a combined "Router/ADSL Modem", then it is DEFINITELY NOT SUITABLE for use with Telewest's cable service.
Surface Pro (2017) vs Surface Pro 4
Where HTML5 is headed next
MacBook Pro v Surface Pro 5
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.