The way it functions is similar to VoIP providers in that its all IP based communications. The difference is that talking on the phone will not impact cable modem speeds for upload or download. There is also a Quality of Service
that is available with CDV
that you do not get with normal VoIP services as the information does not leave the comcast network until it gets put out into the regular phone switch system.Thanks to MrChupacabra *This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Comcast or any of its affiliates.