DSL filter

Typical installation for an existing home involves installing DSL filters on every telephone, fax machine, voice band modem, and other voiceband device in the home, leaving the DSL modem as the only unfiltered device.

In cases where it is possible to run new cables, it can be advantageous to split the telephone line after it enters the home, installing a single DSL filter on one leg and running it to every jack in the home where an analog device will be in use, and dedicating the other (unfiltered) leg to the DSL modem.

If it is not practical to run new cables, it is often still possible to split the telephone line at the point of entry in some cases.

This approach saves considerable money and labor, as the only changes to the premise wiring may occur at the NID and the only additional equipment needed is a 2-line splitter adapter.

If the Line 2 wire pair was originally not connected at the wall jack where the DSL modem is to be used, it may be necessary to complete this step as well.