Voice over Internet Protocol (VoIP) calls received in a Hybrid Fiber Coax (HFC) network (12) maintained by a provider of HFC VoIP telephony services are advantageously translated into a Time-Division Multiplex (TDM) format by an Internet Protocol Device Terminal (IPDT) (26) in the HFC network. Once translated into a TDM format, the call passes to the Public Switched Telephone Network (PSTN) (28) for call processing to afford the call features subscribed to by the called party, such as caller-ID and call waiting. Once processed, the PSTN routes the call to the destination. Likewise, a call destined for an HFC VoIP customer can be processed within the PSTN to afford the call features subscribed to by the HFC VoIP customer. In this way, the HFC VoIP telephony service can offer full-featured VoIP cable telephony without the need to perform call processing in its own network.