Could anyone provide me with a link to documentation, describing how a default queue limit for a particular class is calculated on a ES20-GE3C linecard.
The same policy map applied to interfaces with configured BWs of 1 Gbit/s and 4 Mbit/s produces limits of 16590 and 66 packets respectively for a class with a bandwidth reservation of 40%. I would like to get better understanding of how this was calculated.
Thank you in advance.
1- Forget the queue-limit for the parent policy. It's irrelevant and not used at all. Only the queue-limit of the child policy are used.
2- If you statically configure a queue-limit, this is actually the value used. If you let the router calculated it you could see a different value without traffic and with traffic (Hw updated it when receiving traffic).
3- WRED will work as expected.
Increasing the queue-limit of a class will decrease the chance of drop but will increase the delay and latency for this class.