On the Alcatel-Lucent 7750 SR, what is a slope policy used for?

Question

Options

• ADefining the slope of the TCP slow-start mechanism for self generated traffic.
• BDefining the slope of the scheduling rate per forwarding class when using HQoS.
• CDefining the high and low slope values when deploying buffer admission control for UDP traffic in
• DDefining the high and low slope values when deploying buffer admission control for TCP traffic in
• EDefining the high and low slope values when deploying buffer admission control for TCP traffic in

• A
  3% (1)
• C
  7% (2)
• D
  87% (26)
• E
  3% (1)

Explanation

On the 7750 SR, slope policies configure WRED (Weighted Random Early Detection) behavior - specifically the low and high watermark thresholds that control the probability of dropping packets as a buffer fills. This is fundamentally a TCP congestion-signaling mechanism: by dropping packets before the buffer is completely full, the router signals TCP senders to reduce their rate via congestion control, preventing catastrophic tail-drop scenarios.

Why the distractors are wrong:

• A - TCP slow-start is an end-host algorithm built into the TCP stack; routers don't configure it via slope policies.
• B - Scheduling rates per forwarding class in HQoS are controlled by scheduler policies, not slope policies.
• C - UDP has no built-in congestion response, so probabilistic drop slopes are ineffective and not applied to UDP traffic in this way.
• E - This appears to be a duplicate/truncated version of D; D is the complete, correct statement.

Memory tip: Think of a slope policy as drawing a "ramp of pain" for TCP - a gradual incline from low-drop probability at the low watermark to 100% drop at the high watermark. TCP reacts to drops; UDP doesn't. So slopes are for TCP only.

No community discussion yet for this question.