As part of the package Snapfulfil will provide a dedicated and robust connection to the data centres, with a failsafe backup connection to protect against the unforeseen. These connections will consist of a primary ADSL line from BT and a secondary data line from a different supplier, plus all of the hardware you need to access these connections.
In the event that the primary modem or BT line fails then the connection is automatically transferred to the secondary connection. Since the lines are constantly monitored the original fault will probably be fixed before you are even aware there was a problem.