Connecting VOIP to House

I just switched back to Cox digital phone service after being with Vonage for a number of years. Basically Cox provided a Cisco DPQ3212 DOCSIS 3.0 cable modem supporting both internet and phone services, plus sent a technician to our house to set it up, all at no charge. The Cisco cable modem replaced two devices, our Vonage branded Telephone Adapter (TA) and our existing Motorola Surfboard DOCSIS 3.0 cable modem. We had already disconnected our inside wiring from the PSTN when using the Vonage TA, so it was simply a straight replacement. You can split the services provided by the Cisco cable modem to do phone service only, keeping your existing cable modem to continue to provide internet service, both being hooked up to your coaxial inside wiring simultaneously via splitter if that makes sense in your situation. The Cisco is a very capable device, so we retired the Motorola and use only the Cisco for both phone and internet service. You also might think of using wireless phones, with a base station connected to your IW somewhere else besides your office rather than moving the cable modem there... Best of luck!