The following article addresses issues of concern to all engineers whose areas of technical interest are in one or more of the many communications transmission technologies. These technologies are converging as a result of the maturing of interactive data retrieval systems. Cable television systems are but one of the more important of these technologies. This article offers the reader an update on the current state of standardization in the field of hybrid interactive data networks. It also introduces system modelling which includes, as an important physical subnode, a two-way CATV transmission system interfacing in a larger hybrid interconnected data-based network.