Micro Filters (Splitters)
A micro filter stops the telephone interfering with your ADSL connection, this allows you to use your telephones and Internet connection at the same time.
It is crucial that your telephone line has the correct micro filter set up, failure to do so can result in loss of or intermittent connection to the Internet and noise through your telephone hand set.
How to set up your micro filter correctly
Each telephone socket in your house connected to the line number your broadband is installed on will need a micro filter if it currently has a device plugged into it e.g. fax/telephone/sky box. Any sockets which do not have a device plugged into it will not need a micro filter.
If you have an extension cable between the telephone socket and modem/router you will only need to have a micro filter attached to the end where the modem/router is connected.