To use more than one phone for your TritonVoice service, we recommend using a cordless phone system with more than one handset. Then, connect the main base station to your TritonVoice adapter, and use the cordless handsets in different locations. If you'd like to use the existing phone jacks in your home, please read the following:

If you are replacing your traditional phone service with VoIP you will need to disconnect your inside wiring from the telephone company's outside cables, and then connect your VoIP adapter to your inside wiring.

On the outside of your home, you should find a telephone box shown here:
When you open it (usually by undoing a single common screw), you will be able to access the wires going into your home, but not the ones coming from the street. This is by design. There should also be a ground wire coming out of the telephone company's side of the box. It is important to leave the ground wire connected, since it can help guard against lightning damage to your home (in the event that lightning strikes a nearby phone cable).

Once inside the Network Interface Box, shown here:
you should see one or more sets of screw terminals (two or four screw terminals per line) and short stubs of wire with a standard telephone plug on the end, plugged into a matching jack as shown here.

Warning the phone company
You don't want to remove the interface because someday you might sell your home, and the next person to come along may want phone service. So, here is what we suggest. PLEASE READ THE FOLLOWING TWO PARAGRAPHS CAREFULLY, THEY ARE QUITE POSSIBLY THE MOST IMPORTANT ON THIS PAGE: First, unplug all the plugs and take some black plastic electrical tape (or any other vinyl tape you may have) and wrap the ends of the plugs, so that they cannot be plugged back in without removing the tape. Then, write something like this in bold letters on the cardboard: "ATTENTION TELEPHONE COMPANY: DO NOT RECONNECT THESE CIRCUITS — WILL DAMAGE EQUIPMENT INSIDE!" Shut the lid on the box and screw it and write the same message on the outside of the box as well.

Plugging VoIP in
Once you have disconnected all the lines inside the network interface box, pick up a regular corded telephone inside the home and you should hear nothing — the line should be totally dead. Another test is to push one of the buttons on the phone's touch tone pad, again you should near nothing — no tones, no clicks, just dead silence. Do NOT use a cordless phone for this test, or any phone that uses batteries or an external power supply — the closer you can get to a plain old telephone, the better! Now that you know the line is dead, plug your VoIP telephone adapter into any one of the telephone jacks in your home (using a standard telephone line cord). Connect standard telephones into the other jacks in your home and your whole house is now wired for VoIP.
There is a common misconception that you have to run a wire from the adapter out to the network interface box and connect to the telephone wiring there. Generally speaking, that is not true — telephone jacks are wired in parallel, so you should be able to plug the adapter into any working phone jack, and that will feed the signal to the other jacks in your home.

The following information above is an excerpt taken from the webpage below. If you'd like further in-depth information or have a different telephone interface, feel free to reference it here: http://michigantelephone.mi.org/distribute.html