Dell N1100-ON, Reference Manual

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Layer 2 Switching Commands
705
physical interface. For the Dell EMC NetworkingN2000/N3000 Series
switches, a threshold of 100% corresponds to a buffer occupancy of 295428
bytes queued for transmission on an interface. For the N4000 Series switch, a
threshold of 100% corresponds to a buffer occupancy of 666757 bytes queued
for transmission on an interface.
Use the
classofservice dot1p-mapping command or the classofservice ip-
dscp-mapping command in conjunction with the classofservice trust
command to assign packets to a CoS queue based upon values contained
within the packet.
WRED Drop Probabilities:
Between the minimum and maximum thresholds, the drop probability is
divided into eight discrete levels of increasing probability of packet drop. The
levels are as follows:
0 - 6.25% of maximum drop probability
1 - 18.75% of maximum drop probability
2 - 30.25% of maximum drop probability
3 - 43.75% of maximum drop probability
4 - 56.25% of maximum drop probability
5 - 68.75% of maximum drop probability
6 - 81.25% of maximum drop probability
7 - 92.75% of maximum drop probability
As an example, with a drop probability of 50%, a minimum threshold of 10%
and a maximum threshold of 90%, the drop probability from 10% to 20%
congestion is 3.125%, from 21% to 30% congestion is 9.375%, ...
The drop probability scale supports values in the range 0-10% and the discrete
values 25%, 50%, 75%, and 100%. Other values are silently truncated to the
next lower value by the hardware.