I have switched to Comcast Voice from Verizon. I have a Motorola Surfboard SB6121 cable modem that I own. I need to buy an adaptor to go with this modem to facilitate voice service. The outsourced Comcast voice chat person told me I needed an "ethernet chord" to make this work. I googled ethernet chord and then realized that the person meant cord not chord. At any rate; there is some sort of adaptor that I can purchase or rent that will allow me to hook my home phone system into my existing modem. Anyone know which one I need?
For CDV you need what is called a eMTA which is a telephony modem. There is no adapter for your existing unit. A eMTA does both CDV and HSI.
You have a few choices:
Keep your existing modem for HSI and add a rented eMTA for CDV. Rented eMTA's from Comcast are $7 a month in most area's.
Unhook the existing cable modem and add a rented eMTA for both HSI and CDV for $7 a month.
Unhook the existing cable modem and in some area's you can buy a eMTA. This is not a nationwide program. Select Best Buy's with Comcast Connection Centers have these D3 Arris TM722G for sale. The list of stores is HERE They are $150 plus tax & the cost of a Comcast tech to come out and install it. If your area is listed, look for the Comcast Sales Rep in the BB TV section with the red or black shirt.