Implementing Cisco IP Telephony and Video Part 1 (CIPTV1, legacy) — Question 18

Which three descriptions are true? (Choose three.)

Answer options

• A. The class of service is a parameter that is used for traffic classification and marking at Layer 2.
• B. The IP precedence is a parameter that is used for traffic classification and marking at Layer 2.
• C. The differentiated services code point is a parameter that is used for traffic classification and marking at Layer 2.
• D. The class of service is a parameter that is used for traffic classification and marking at Layer 3.
• E. The IP precedence is a parameter that is used for traffic classification and marking at Layer 3.
• F. The differentiated services code point is a parameter that is used for traffic classification and marking at Layer 3. AEF

Correct answer:

Explanation

The correct answers are A, D, and F. A is correct because the class of service (CoS) operates at Layer 2. D is also correct as CoS can be used for Layer 3 traffic. F is correct because the differentiated services code point (DSCP) is used for Layer 3 traffic classification. B and E are incorrect as IP precedence is not used for Layer 2; it is a Layer 3 mechanism.