What Is the Purpose of the DSL Filters on Phone Jacks in Your Home?

What Is the Purpose of the DSL Filters on Phone Jacks in Your Home?

What Is the Purpose of the DSL Filters on Phone Jacks in Your Home?

A DSL filter is used to keep home telephone and DSL Internet signals from interfering with each other, allowing the phone to work correctly. This is necessary in a building where both services are supplied by the telephone company and use the same wires.

A low-frequency device such as a telephone can not process higher DSL frequencies, so an unfiltered phone may not work or may cause interference to a DSL modem. A DSL filter, which is a low-pass filter, allows telephone frequencies to pass through it while restricting the higher DSL signal. These filters are passive devices and do not use power. A filter is never used with a DSL modem.