WRED vs Tail drops

[matt.eason]

Hi team,

My question relates to WRED and some of it configurable parameters. I have configured WRED on the class-default queue inside a CBWFQ configuration. It is working as expected.

The class-default queue is quite heavily utilised as such I not only see random drops but also tails drops. About 75% of the drops are WRED with other 25% being tail drops.

Should I be aiming to eliminate tail drops all together and if so would you suggest I increase the MPD so WRED starts dropping more packets when the queue builds up or should I modify the min/max queue thresholds to start dropping packets earlier.

Thanks,

[Lei Tian]

Hi Matt,

I think you can consider adjust the queue limit and also the min/max threshold, so low priority traffic will be dropped more aggressive.

HTH,

Lei Tian