a) After I bought the Arris modem privately, and installed it successfully, and activated it (with a walk-through from Comcast), it works fine for all things internet.
b) What it won't do is "show up" on any list of my equipment, and it won't allow me to see any on-demand xfinity content through my computer.
c) When I called comcast about this, a nice-sounding south Asian assistant walked me through the activation process again, and as a last step his screen pulled up: "This is not an approved modem. Recommend the customer bring this in, and buy one from us."
He read the screen to me with some level of puzzlement. Since Comcast sells and provides guidance for the TG1682, why won't they "approve" it for me?