Today's cable systems are in a unique position to deliver telephony services via the two-way transmission of digital signals. Several methods exist for combining telephony and entertainment video signals within the distribution plant and for separating those signals at the subscriber end of the system. Each of these methods has unique technical and economic advantages and disadvantages.
This paper discusses the architectural and design considerations when developing a network capable of delivering telephony services. Architectural options are outlined, and the tradeoffs associated with design choices are discussed. Node sizing, optimization, and evolution are considered, as well as fiber counts, bandwidth utilization, reliability and redundancy, network management, and subscriber terminal deployment.