Final answer:
A cable modem termination system (CMTS) for coaxial connections or an optical line terminal (OLT) for fiber-optic connections connects multiple cable connections to an ISP's core network. These devices function as aggregation points for customer data and interface with the ISP's broader infrastructure.
Step-by-step explanation:
The device that connects multiple cable connections to an Internet Service Provider's (ISP's) core network is typically known as a cable modem termination system (CMTS) for coaxial cable-based systems, or an optical line terminal (OLT) for fiber-optic connections. These devices aggregate traffic from many customers and route it to the ISP's core network. In the case of coaxial cables, they consist of two concentric conductors separated by insulation, as described in Figure 9.18, and are proficient for audiovisual connections. The transition to broadband connections has enabled ISPs to use cable television lines and even dedicated lines to manage the increased volume of internet data flow effectively.
Before broadband technology's widespread adoption, television networks relied on local affiliates and their transmission towers for broadcasting. Those towers could only cover a limited area, so a network of affiliates was necessary to reach a national audience. However, with the advent of cable and fiber optics, this dependency has declined as cable networks now transmit signals to homes directly without needing local affiliates.