X4S AC3200 Compatibility with Xfinity VoIP

[drh4625]

Prior to commiting to Xfinity for a VoIP conversion is this cable modem compatable for a landline configuration?

[plemans]

No, the C7800 doesn't have a voice component. You can add an aftermarket like Ooma but not one from your ISP. 

The compatible modem/router/voice for xfinity is the C7100V.  But its only docsis 3.0 and not 3.1. 

Or you could get a modem with voice (like the CM1150V) and use your own router. Then you'd have docsis 3.1, a voice component, and a router that you controlled the firmware on and not your isp (like the combo devices)

[michaelkenward]

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@plemans wrote:

Or you could get a modem with voice (like the CM1150V) and use your own router.

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An option favoured by many people who don't like a combined modem/router, partly because it gives you a much better choice of router features.