Click the exhibit button below. Given that the slope-policy (below) has been enabled and applied on a network port, which of the following statements are TRUE? (Choose three)

Question

Exhibit

Options

• AAll out-of-profile traffic will be dropped before any in-profile is dropped.
• BThe time average factor of 0 will discard all packets arriving in the shared buffer pool.
• CWhen the shared buffer utilization reaches 51%, in-profile packets might be dropped.
• DThe highest probability with which an out-of-profile packet can be dropped is 20%.
• EWhen an in-profile packet arrives and the shared buffer utilization is at 69%, the packet will have

• A
  66% (40)
• B
  11% (7)
• D
  23% (14)

Explanation

Why A, C, and E are correct:

A is correct because slope policies are designed so the out-of-profile (red) curve reaches 100% drop probability at a buffer fill level where the in-profile (green) curve hasn't yet started dropping. This guarantees out-of-profile traffic is fully purged before any in-profile packet is touched - a core guarantee of WRED/slope-based QoS.

C is correct because the exhibit shows the in-profile slope begins at approximately 50% shared buffer utilization. At 51%, you've crossed the low threshold of the in-profile curve, meaning probabilistic dropping can begin (note "might" - it's not certain yet, just possible at low probability).

E is correct because at 69% buffer utilization, the in-profile traffic is well into its drop slope (between the low and high thresholds), so arriving in-profile packets face a meaningful - and deterministic based on the curve - drop probability per the policy's configured slope.

Why B and D are wrong:

• B is wrong - A time average factor (TAF) of 0 means no exponential smoothing of the queue depth average (instantaneous measurement only); it does not cause all packets to be discarded.
• D is wrong - Out-of-profile packets can be dropped with up to 100% probability once buffer utilization hits the out-of-profile high threshold. The 20% value likely refers to the starting drop probability at the low threshold, not the maximum.

Memory tip: Think of it as a two-lane highway closing in a storm - the "out-of-profile" (secondary) lane closes completely before the "in-profile" (priority) lane is touched at all.

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