Cisco Certified Support Technician (CCST) NetworkingIP ServicesHard
A company is experiencing issues with its VoIP calls dropping and audio quality degradation during peak network usage. A network engineer is tasked with implementing a QoS mechanism to prioritize VoIP traffic over less time-sensitive data. Which QoS mechanism is designed to handle network congestion by actively dropping lower-priority packets to protect higher-priority traffic?
- ACongestion Management
- BCongestion Avoidance
- CTraffic Shaping
- DTraffic Policing
Show answer & explanationAnswer & explanation
Correct answer: D. Traffic Policing
Traffic Policing actively enforces configured traffic rates by dropping or remarking packets that exceed the defined limits. This is an immediate action taken when traffic violates the policy, making it suitable for protecting critical services like VoIP during congestion.
Why the other options are wrong
- A. Congestion Management uses queuing to prioritize and schedule packets during congestion, not actively drop based on rate.
- B. Congestion Avoidance tries to prevent congestion before it occurs by dropping packets randomly.
- C. Traffic Shaping buffers excess traffic to smooth out the flow, not actively drop it.
QoS Traffic Policing
Traffic Policing is a QoS mechanism that strictly enforces traffic rates by actively dropping or remarking packets that exceed a configured threshold. It's an immediate action taken at the ingress of a network device to protect network resources.
- Strictly enforces traffic rate limits.
- Actively drops or remarks non-conforming packets.
- Used at ingress to protect network resources.
- Can lead to packet loss for non-conforming traffic.
Memory trick: Police cars drop the rule-breakers.