How to Connect a Fax Machine to Cable Internet

Your company's high-speed cable Internet connection not only provides Internet access to any computers in your office, but is also capable of adding landline telephone service to your office. With a subscription to your cable Internet service provider's telephone service, you can also connect and use a fax machine and an answering machine, if desired. The connection is via the modem's telephone ports and with a splitter if the modem only contains a single telephone port. Splitters are available at computer, electronics and retail superstores as well as online electronics outlets.

Place a fax machine next to the modem and plug in the machine's power cable.

Turn your cable modem around so the back of the device is facing you. Locate the modem port that is labeled “Telephone,” “Telephone Out” or something similar. Your modem may contain two Telephone ports -- one with a cable running to your telephone and one that doesn't contain a cable.

Connect a telephone cable to the port on the back or side of your fax machine. Connect the other end into the telephone port on the modem, labeled “Telephone,” “Telephone Out” or something similar.

Plug an RJ-11 telephone line splitter into the telephone port on the modem, if the cable modem only contains one telephone port. Plug the fax machine's telephone cable into one of the ports on the splitter, and then plug the other end of the telephone cable into the splitter's other port.

Turn on your fax machine and send a test fax to a business associate; clearly state on the fax that it is a test. You will hear a dial tone and your fax machine connecting to the other party's fax machine when you send the fax. If you don't hear a dial tone or the fax connecting, check the connection.