Configuring WRED Templates

With a WRED template, you can set the parameters for processing packets of three colors, that is, red, yellow, and green. Generally, green packets have the smallest discarding probability and the highest thresholds (both lower and higher); yellow packets have the medium discarding probability and thresholds; the red packets have the highest discarding probability and the lowest thresholds.

By configuring a WRED template, you can set the upper threshold, lower threshold, and discarding probability for queues.

• When the length of a queue is below the lower percentage threshold, no packet is dropped.

• When the length of a queue is between the lower and upper percentage thresholds, incoming packets are dropped randomly. The longer the queue, the higher the discarding probability.

• When the length of a queue exceeds the upper percentage threshold, all the incoming packets are dropped.

You can configure limits and discarding probability for packets of every color.

• If you do not configure a port-wred object, the system uses the default tail-drop policy.

• You can configure the smallest upper and lower percentage thresholds for the queue containing red packets, medium upper and lower percentage thresholds for the queue containing yellow packets, and the highest upper and lower percentage thresholds for the queue containing green packets.

• In actual configurations, it is recommended that the lower percentage threshold for WRED start from 50%, with the thresholds for packets of different colors being adjusted accordingly. The recommended discarding probability is 100%.

Do as follows on the router: