Dial-up data communications: What is the name given to the exchange of control signals required to establish a connection between the modem+computer at one end of a line and the modem+computer at the other end?

Introduction:
Before data transfer can occur over dial-up or other circuit-oriented links, endpoints must synchronize their parameters. This preliminary exchange ensures both sides agree on speeds, modulation, compression, and error control. Recognizing the term for this process is essential in legacy networking and still relevant conceptually in modern link negotiation.

Given Data / Assumptions:

• Two modems and their attached computers attempt to form a reliable link.
• Control signals and messages precede payload data.
• We want the standard term for this negotiation.

Concept / Approach:
Handshaking refers to the initial signal exchange that sets up communication parameters. In classic modems, this includes carrier detection, training sequences, and feature negotiation (e.g., error correction, compression). While “protocol” is the broader set of rules governing communication, handshaking is the specific connection-establishment phase. “Duplexing” describes simultaneous send/receive capability, not the negotiation itself.

Step-by-Step Solution:
1) Identify the need: agree on link parameters prior to data.2) Name the process: handshaking.3) Distinguish from generic terms like protocol or duplexing.4) Choose “Handshaking.”

Verification / Alternative check:
Audible modem “tones” during dial-up were the handshaking and training sequences setting modulation profiles and speeds.

Why Other Options Are Wrong:

• Modem options: configuration choices, not the negotiation process.
• Protocol: too broad; encompasses the entire rule set, not just connection establishment.
• Duplexing: describes directionality, not the setup handshake.
• None of the above: invalid because handshaking is correct.

Common Pitfalls:
Using “protocol” as a catch-all; precise terminology distinguishes phases like handshaking from ongoing data transfer.

Final Answer:
Handshaking