Which statement differentiates RED from WRED?

Which statement differentiates RED from WRED?

• A. RED Does Not Selectively Drop Based On Service Levels; High/Low Priority Have The Same Probability
• B. RED Uses Per-Service-Level Thresholds
• C. RED Drops Only Low-Priority Packets
• D. RED Drops High-Priority Packets More

Answer: (A)

The key idea is how congestion signals are applied to different traffic. RED (Random Early Detection) signals congestion by dropping packets randomly as the average queue length grows, but it treats all packets the same—priority or class doesn’t influence the drop probability. That means high- and low-priority traffic have the same chance of being dropped in RED. WRED (Weighted RED) changes this by introducing per-class thresholds and different drop probabilities, so the traffic with higher priority is less likely to be dropped than lower-priority traffic. That’s why the statement that RED does not selectively drop based on service levels captures the fundamental difference. The other options describe features that belong to WRED, not RED.

The key idea is how congestion signals are applied to different traffic. RED (Random Early Detection) signals congestion by dropping packets randomly as the average queue length grows, but it treats all packets the same—priority or class doesn’t influence the drop probability. That means high- and low-priority traffic have the same chance of being dropped in RED.

WRED (Weighted RED) changes this by introducing per-class thresholds and different drop probabilities, so the traffic with higher priority is less likely to be dropped than lower-priority traffic. That’s why the statement that RED does not selectively drop based on service levels captures the fundamental difference. The other options describe features that belong to WRED, not RED.