What will I need to get online with Fast4? You will need a single BT phone line, unfortunately our service will not work with other providers such as NTL or cable (please call our service centre if unsure). Together with this you may either use a 56k modem (v90 or v92), a single ISDN/BT Highway at 64k or and ADSL modem or router. You can check if you will be able to connect to system by telephoning 0808 991 6234. If you get a response from the computer then the line should connect. If the line states that the number is not available, you will not be able to connect and our service unfortunately will not work with your connection.