Broadband Daily:: It is official – Earthlink is launching Earthlink Unlimied Voice and target its million odd broadband subscribers. The service is powered by Vonage, the broadband phone service. With this move, EarthLink becomes the first ISP to offer a viable competitive residential phone service. EarthLink also becomes the first competitive ISP carried by major cable operators that is using its cable-based broadband platform for providing a commercial service that extends beyond traditional ISP functionality. The EarthLink-Vonage voice service, however, is available only on the Time Warner systems, with EarthLink cable modem customers in Comcast and Charter service territories unable to opt for the VoIP option. EarthLink execs seem unclear about why only Comcast and Charter customers can?t receive the low-cost telephony option while one Vonage executive thinks that Earthlink contracts with Comcast and Charter block Earthlink from offering VoIP and the ISP is trying to renegotiate those deals. Time Warner is the only system Earthlink can offer this service for now. Still it could be a net net win for the ISP which has been losing some steam since the rise of the discount ISPs.