How to Connect All Your Home Phones to Your VoIP Service

Try this hack with your landline phones

Young Woman Using Cordless Phone
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The telephone system you grew up with is a Public Switched Telephone Network (PSTN)—a landline, in modern parlance. Many homeowners and business owners have switched to Voice over Internet Protocol (VoIP), which places voice calls over the internet. If you want to make use of your conventional phone sets while using VoIP service, you can connect your home or office phones to your VoIP service. To do this, you need a broadband internet connection and an Analog Telephone Adapter (ATA).

Whether you have one phone set or more, they are linked together by modular jacks. A modular jack is a small box linking one or two phone wires. Your phone wiring closes at the point of entry of your telephone service, a gray or brown box affixed by your phone company to your house. This box is called the demarc and is the point where your home connection is linked to the service’s network.

How to Connect Traditional Phones to VoIP

To connect your traditional phone sets to VoIP:

  1. Disconnect your house or office from the PSTN phone company service. This is a security measure to prevent the ATA from burning out due to power from the PSTN line. To do this, go to the demarc and open it. There are two series of wires: one going into the building to your phones and the other going outside to the provider’s network. Disconnect the one going to the outside to disconnect the phones from the PSTN.
  2. Pick up a phone to confirm that the PSTN service is disconnected. If you don't hear a dial tone, the phone line is disconnected. (If you have already terminated your PSTN service, you won't be able to check this.)
  3. Confirm that your VoIP service is working.
  4. You now have an isolated internal phone circuit. Connect the ATA to any modular jack in your phone circuit using an RJ-11 connector. Pick up a phone to check for a tone. If there is a tone, this hack worked.

Most ATAs are designed to handle the power requirements of only one or two phones, so check the ATA specifications to know how many phones the circuit can support. It is better to know the number of phones you have before buying the ATA so that you can choose one with adequate power.

Note: Some households receive their broadband connection over an Asymmetric Digital Subscriber Line (ADSL). This tip won't work if the ADSL service uses your PSTN wiring. There should be different cabling for it.