Which statement correctly describes RED (Random Early Detection)?

Which statement correctly describes RED (Random Early Detection)?

• A. It Drops Packets Randomly As The Queue Length Increases, Without Using IP Precedence
• B. It Drops Packets Based On Destination
• C. It Drops High-Priority Packets More
• D. It Uses Strict Priority To Drop High-Priority Packets

Answer: (A)

RED is a congestion avoidance mechanism that signals congestion before a router’s queue gets full. It works by watching the average queue length and, as that average grows beyond a small threshold, starts dropping arriving packets randomly. The chance of dropping increases with the queue size, spreading drops across many flows rather than letting one keep filling the queue. This helps prevent global TCP synchronization and keeps the network operating more smoothly. Importantly, RED does not drop packets based on where they’re going (destination) or on per-packet priority. It doesn’t use IP Precedence to decide which packets to drop. In its standard form, drop decisions are tied to queue state and a probabilistic rule, not to traffic class or destination. Some variants exist (like ECN marking or WRED) that add different behaviors, but the essence of RED is random early drops driven by queue length, not by destination or priority.

RED is a congestion avoidance mechanism that signals congestion before a router’s queue gets full. It works by watching the average queue length and, as that average grows beyond a small threshold, starts dropping arriving packets randomly. The chance of dropping increases with the queue size, spreading drops across many flows rather than letting one keep filling the queue. This helps prevent global TCP synchronization and keeps the network operating more smoothly.

Importantly, RED does not drop packets based on where they’re going (destination) or on per-packet priority. It doesn’t use IP Precedence to decide which packets to drop. In its standard form, drop decisions are tied to queue state and a probabilistic rule, not to traffic class or destination. Some variants exist (like ECN marking or WRED) that add different behaviors, but the essence of RED is random early drops driven by queue length, not by destination or priority.