When you dial a phone number using the ship’s analog phone, the TracPhone system converts its analog signal into digital VoIP data and transmits it over the mini-VSAT Broadband network to an Internet-based SIP (session initiation protocol) server. The digital VoIP data is then converted back into its original analog signal and routed via a proxy server to the appropriate public switched telephone network (PSTN). Finally, the telephone network’s carrier completes the call to ring the desired shore phone line.
Voice Service Call Routing