QoS - WRED traffic profile thresholds
Weighted Random Early Detection (WRED) is a QoS mechanism used to manage the tail end of a queue, and in particular, to mitigate against TCP global synchronization.
Refer to the following traffic profile of a particular WRED configuration:
This particular traffic profile has the following thresholds:
- Minimum threshold: 20 packets
- Maximum threshold: 45 packets
- MPD (Mark Probability Denominator): 25%
These values can be configured of course. For this specific example:
- for average queue depth values between 0 and 20, there are zero drops.
- for average queue depth values between 20 and 45 there is an increasing number of drops depending upon the queue depth.
- for average queue depth values exceeding 45, all packets are dropped.
For queue depth values between 20 and 45, the percentage of dropped packets goes from 0 to a maximum of 25%. The MPD is that value of 25%.
Links:
https://forum.networklessons.com/t/wred-weighted-random-early-detection/5130/39?u=lagapides