Nokia Certified Network Associate (NCNA) — Question 5

What is the function of Layer 2?

Answer options

• A. Layer 2 is responsible for encapsulating packets into frames for transmission on physical media.
• B. Layer 2 is responsible for encapsulating packets into IP datagrams and routing them.
• C. Layer 2 is responsible for encapsulating application data into TCP/UDP messages.
• D. Layer 2 is responsible for the timing of the signals on physical media.

Correct answer: D

Explanation

The correct answer is D because Layer 2 is responsible for ensuring that signals are timed correctly for transmission on physical media. Options A, B, and C describe functions related to higher layers in the OSI model, such as framing, routing, and transport, which are not the primary responsibilities of Layer 2.