If communication software is the “traffic cop” of a microcomputer communication system (managing control and rules), what role best describes the modem in that system?

Introduction:
A modem (modulator–demodulator) converts digital signals from data terminal equipment into analog waveforms suitable for telephone lines and converts received analog signals back to digital. The question uses an analogy: if software enforces rules like a “traffic cop,” what is the modem’s comparable functional role?

Given Data / Assumptions:

• Microcomputer with communication software and a modem connected to a telephone or carrier line.
• Software manages sessions, protocols, and user interaction.
• We are mapping device function to an intuitive label.

Concept / Approach:
The modem sits at the boundary between the digital world (DTE) and the analog carrier network (PSTN or similar). Functionally, it is the interface that adapts signal formats, line levels, and timing so that two unlike systems can communicate.

Step-by-Step Solution:

Verification / Alternative check:
Many textbooks call the modem the “interface” between DTE and communication line, emphasizing its conversion function. “Bridge” has a specific LAN meaning that does not fit dial-up modems; “link” describes a connection, not the converter.

Why Other Options Are Wrong:

• Park: a place, not a communications function.
• Bridge: a Layer-2 LAN device, not the DTE–PSTN converter here.
• Link: describes the connection itself, not the converting hardware.
• None of the above: incorrect because interface fits precisely.

Common Pitfalls:
Confusing network topology terms with device roles; assuming “bridge” generically means any connector.

Final Answer:
Interface.