A network administrator applies a Quality of Service (QoS) policy to an ingress interface of an enterprise router to cap incoming data transfers at a rate of 10 Mbps. During peak usage periods, application traffic exceeding 10 Mbps experiences immediate packet drops rather than transmission delays. Which statement accurately explains why this traffic behavior occurs?
- Traffic policing is configured on the interface, which drops or remarks out-of-profile traffic exceeding the rate limit without buffering packets.Answer
- BTraffic policing buffers non-conforming packets in software queues until the burst ends, but packet drops occur because the queue limit is reached.
- CTraffic shaping is active on the ingress interface, but shaping policies drop packets by default when applied in the inbound direction.
- DTraffic policing automatically converts excess traffic into low-priority Class of Service (CoS) frames, which are then dropped by ingress switch interfaces.
Answer
Traffic policing is configured on the interface, which drops or remarks out-of-profile traffic exceeding the rate limit without buffering packets.
Traffic policing meters bandwidth usage against a specified rate limit. When traffic exceeds this target rate (the Committed Information Rate), the policer immediately drops the non-conforming traffic or remarks its DSCP/IP Precedence value. Because policing does not buffer packets, bursty traffic above the limit experiences immediate packet loss.
Step-by-Step Solution
Key Concept
Operational differences between QoS Traffic Policing (dropping/remarking without queues) and Traffic Shaping (buffering/smoothing)