Cisco Certified Network Associate (CCNA) Practice Exam

What happens on a Frame Relay network when the CIR is exceeded?

1. All traffic is queued for later transmission

2. Traffic is dropped without warning

3. All excess traffic is marked as discard eligible

4. Traffic will be rerouted to a different path

The correct answer is: All excess traffic is marked as discard eligible

In a Frame Relay network, when the Committed Information Rate (CIR) is exceeded, the behavior of the network is designed to manage excess traffic efficiently. The correct answer indicates that all excess traffic is marked as "discard eligible." When a frame exceeds the CIR, it is classified as excess traffic, meaning it may be subject to being dropped if the network is congested. This marking as discard eligible allows the Frame Relay network to provide a balance between quality of service and efficient use of bandwidth. Frame Relay is a cost-effective solution that prioritizes committed traffic while still allowing for bursts of excess usage when needed, understanding that some excess traffic may not be delivered under high load conditions. This mechanism ensures that important or critical data can be prioritized while still allowing for higher data volume when the network permits. Each data frame is treated based on its eligibility for being discarded if there is congestion, facilitating a more efficient management of bandwidth resources. Other options do not accurately reflect the behavior of Frame Relay when the CIR is exceeded. For example, queuing all traffic would not reflect the typical management style of Frame Relay, which is focused on efficient bandwidth use. Traffic that is simply dropped without warning does not capture the importance of marking excess traffic. Lastly, rer