Step 1 – Install DSL filters on every telephone jack that has a phone or a device that connects to the phone line. DSL filters separate voice and DSL signals in the telephone line. Without filters, your modem will receive interference from your telephone, which will cause your Internet connection to be slow or drop out. The filter will also remove interference caused by the modem. To resolve these issues, purchase a DSL filter from your Internet service provider or a local store that sells networking equipment. To install a DSL filter, remove the telephone line from the jack. Connect the filter into the wall jack. Plug the telephone line into the filter.
Step 2 – Do not use telephone cords that are longer than 12 feet. The longer, the cord, the farther the DSL signal has to travel, which will cause your connection to be slow and eventually drop. To gain the strongest signal, use the telephone cord that came with your modem. If your modem will be farther than 12 feet from your phone jack, have your telephone provider, Internet service provider, or a certified professional install additional telephone jacks in your home.
Step 3 – Have your Internet service provider or a professional install a splitter on your Network Interface Device (NID). The NID is the box on the outside of your home that holds your telephone and network wires. Because the modem and telephone share the same line, they interfere with one another, causing static in the telephone line and drops in the Internet connection. A splitter installed on the NID will eliminate the interference and the need for filters. The DSL signal will only be routed to one telephone jack. If you choose to connect your modem in a different jack, you will have to contact your Internet service provider or a certified professional to have the splitter re-routed.