Which statement best describes why WRED is useful in networks where the majority of traffic is TCP?

Which statement best describes why WRED is useful in networks where the majority of traffic is TCP?

• A. TCP packets that are not dropped must be retransmitted
• B. TCP sources reduce traffic flow when congestion occurs.
• C. TCP packets must have priority over UDP packets.
• D. TCP packets cannot arrive out of sequence.

Answer: (B)

WRED is an active queue management approach that drops some packets before the queue is full, creating an early signal of congestion. In TCP, packet loss is the trigger for the sender to reduce its sending rate, adjusting the congestion window downward. When most of the traffic is TCP, these early, probabilistic drops cause senders to back off sooner, preventing queue buildup, reducing the chance of a severe congestion collapse, and helping keep overall throughput stable with lower delays. So the statement that best describes WRED’s usefulness is that TCP sources reduce traffic flow when congestion occurs because the loss signals they should back off. The other ideas don’t capture how TCP responds to loss or how WRED uses early drops to steer traffic away from congestion.

WRED is an active queue management approach that drops some packets before the queue is full, creating an early signal of congestion. In TCP, packet loss is the trigger for the sender to reduce its sending rate, adjusting the congestion window downward. When most of the traffic is TCP, these early, probabilistic drops cause senders to back off sooner, preventing queue buildup, reducing the chance of a severe congestion collapse, and helping keep overall throughput stable with lower delays. So the statement that best describes WRED’s usefulness is that TCP sources reduce traffic flow when congestion occurs because the loss signals they should back off. The other ideas don’t capture how TCP responds to loss or how WRED uses early drops to steer traffic away from congestion.