What type of device is primarily responsible for establishing and terminating communication links?

The Data Communication Equipment (DCE) plays a crucial role in establishing and terminating communication links within a network. DCE refers to devices that provide a means of connection to a network, enabling data transmission between different devices. This includes modems, multiplexers, and other equipment that prepare the data for transmission over a communication channel.

The primary function of DCE is to manage the communication process, ensuring that data is correctly formatted and delivered to the intended destination. This includes controlling the signaling and timing aspects of the communication, making it essential for establishing and managing connections.

In contrast, other options like Data Terminal Equipment (DTE), Network Interface Cards (NICs), and Repeaters serve different roles. DTE refers to devices that act as endpoints in a communication link (like computers or terminals), while NICs facilitate the connection between computers and a network but do not inherently establish or terminate communication links. Repeaters amplify signals to extend the distance over which data can travel in a network, but they do not handle the establishment or termination of communication links. Thus, DCE is correctly identified as the type of device primarily responsible for these tasks within a network.