At what point does a DOCSIS modem secure authorization for high-speed data (HSD) service?

The correct response highlights that a DOCSIS modem secures authorization for high-speed data (HSD) service upon receiving a registration response message that contains a service identifier (SID). This process is a critical step in establishing a connection to a broadband service provider’s network.

When a DOCSIS modem is powered on, it goes through a series of initialization processes, including binding to the RF frequencies and downloading configuration files. However, securing authorization specifically requires a successful registration response indicating that the service provider recognizes the modem and grants it access to the network. The inclusion of the service identifier (SID) in this response is essential because it verifies that the modem is authorized to access the specific service plan associated with that identifier.

Other steps in the process, such as physical installation and the initial power cycle, do not determine when authorization occurs. While installation is necessary for the modem to establish a physical connection and power cycling may initiate various checks, it is the successful reception of the registration response that confirms the modem's authorization to access high-speed data services.