Digi TransPort User Manual page 303

WRED Queue Length Weight factor
The value in this text box specifies a weighting factor to be used in the WRED algorithm when
calculating the weighted queue length. The weighted queue length is based on the previous
queue length and has a weighting factor that may be adjusted to provide different transmit
characteristics. The actual formula used is:
new_length = (old_length * (1-1/2^n)) + (current_length * 1/2^n)
Small weighting factor values result in a weighted queue length that moves quickly and more
closely matches the actual queue length. Larger weighting factor values result in a queue
length that adjusts more slowly. If a weighted queue length moves too quickly (small
weighting factor), it may result in dropped packets if the transmit rate rises quickly but will
also recover quickly after the transmit rate tails off. If a weighted queue length moves too
slowly (large weighting factor), it will allow a burst of traffic through without dropping packets,
but may result in dropped packets for some time after the actual transmit rate drops off. The
weighting factor should be selected carefully to suit the type of traffic using the queue.
Related CLI commands
Entity
qprof
qprof
qprof
qprof
qprof
qprof
qprof
Examples
To display a queue profile, enter the following command:
gqprof <instance> ?
Where
<instance>
To change the value of a parameter, use the following command:
qprof <instance> <parameter> <value>
To set the maximum throughput for queue profile 5 to 10kbps, enter the following command:
qprof 5 maxkbps 10
Digi TransPort User Guide
Instance Parameter
n minkbps
n maxkbps
n qlen
n minth
n maxth
n mprob
n wfact
is the number of the queue profile to be displayed.
Values
0 - 2147483647
0 - 2147483647
0 - 2147483647
0 - 2147483647
0 - 2147483647
0 - 100
0 - 2147483647
Queue Profiles parameters
Equivalent Web Parameter
Minimum kbps
Maximum kbps
Maximum Packet Queue
Length
WRED Minimum Threshold
WRED Maximum Threshold
WRED Maximum Drop
Probability (%)
WRED Queue Length Weight
factor
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