ACA Quality of Service & Traffic Management 3

Question 1

What is the key difference between traffic shaping and traffic policing?

Accepted Answer

Shaping buffers excess packets to smooth traffic; policing drops or re-marks excess packets immediately

Answer

Traffic shaping delays excess packets in a buffer to conform to the rate limit, producing a smooth output; policing immediately drops or re-marks packets that exceed the rate.

Question 2

Which queuing mechanism uses multiple queues with configurable weights to distribute bandwidth proportionally?

Accepted Answer

Weighted Round Robin (WRR)

Answer

Weighted Round Robin (WRR) cycles through multiple queues and services each according to its configured weight, guaranteeing proportional bandwidth distribution.

Question 3

On Aruba AOS-CX switches, where are QoS policies most commonly applied to enforce traffic prioritization?

Accepted Answer

On ingress and egress interfaces using QoS profiles

Answer

On Aruba AOS-CX, QoS schedules and policies are applied to physical or LAG interfaces at ingress (classification/remarking) and egress (scheduling/queuing).

Question 4

What is 'jitter' in the context of network QoS for real-time applications?

Accepted Answer

The variation in packet arrival delay over time

Answer

Jitter is the variation (inconsistency) in packet delay over time; excessive jitter degrades real-time applications like VoIP and video conferencing because packets arrive unevenly.

Question 5

Which DSCP Assured Forwarding (AF) class is recommended for interactive video conferencing traffic?

Accepted Answer

AF41 (DSCP 34)

Answer

AF41 (DSCP 34) is the recommended marking for interactive video traffic per RFC 4594, providing high-priority assured forwarding with low drop probability.

(ACA) Aruba Certified Associate Certification Practice Test

(ACA) Aruba Certified Associate Certification Practice Test

ACA Quality of Service & Traffic Management 3