The deployment of high-speed data services over all-coax and Hybrid Fiber-Coax (HFC) networks is forcing cable operators to quickly develop an understanding of high-speed data multiplexing. Traditional Internet engineering focuses on local area network design, backend network technology and topology, and connection to wide-area or regional networks. In addition, the emergence of different varieties of Cable Modem Termination Systems at the head-end has met with some interesting challenges related to incremental growth, scalability, and matching data channels to RF trunks in a scalable and cost effective manner. This paper overview engineering design issues associated with aspects of high-speed data multiplexing and the incremental re-ordering of the networks to effectively meet growth starting from sparse subscriber deployment and continuing to large take rates.