What is a splitter/filter and do I need one?
A splitter or line filter separates the standard phone line signals from the DSL signals. This is required in order to use the phone line for standard phone handsets, modems, fax machines or other devices that require the phone line. Most of the DSL equipment available requires a splitter or filter in order for you to use your phone service. A few of the DSL modem/routers come with a built in splitter or filter. The specification sheet for the modem/router will usually tell you if this device is inbuilt.
