Which protocol is utilized to download configuration files to DOCSIS modems?

The correct answer is Trivial File Transfer Protocol (TFTP) because this protocol is specifically designed for transferring files quickly and efficiently over a network, particularly in scenarios requiring little overhead. TFTP is frequently utilized for downloading configuration files to DOCSIS modems due to its simplicity and the fact that it operates on a connectionless basis, which minimizes the need for complex setup or management.

In the context of DOCSIS modems, TFTP allows for the transfer of operational and configuration information that the modems need to function correctly on a broadband network. This protocol does not require extensive user authentication or complicated command structures, making it ideal for automated and remote updates in network environments where quick deployment of configuration files is essential.

The other protocols mentioned do not serve the specific purpose of lightweight and efficient file transfer for configuration files in the same manner that TFTP does. For instance, FTP, while capable of transferring files, has more overhead and complexity than is necessary for the straightforward task of delivering configuration files to DOCSIS hardware. Meanwhile, SMTP is focused on sending email messages, and HTTP is primarily used for web content delivery. Thus, they are not suited for the specific needs of configuration file transfers to DOCSIS modems.