Broadband Basics What does ADSL stand for?   What is a modem?   What does 'always on' mean?   Can I use the telephone at the same time?   What are ADSL filters and what do I need to do with them?   How do I get more ADSL filters for BT Yahoo! Broadband with modem?   What is the difference between ADSL broadband and a leased line?   What modem do I get with BT Yahoo! Broadband with modem?   Can I have more than one ADSL connection, for redundancy/up time?