12-10
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 12 Sharing Bandwidth Fairly During Congestion
Configuring Fair Bandwidth Sharing During Congestion
Step 4
Router(config-pmap-c)#
queue-limit
number-of-packets
(Optional) Specifies the maximum number of packets that the
queue can accumulate for this class.
number-of-packets
is a number from 1 to 64. The default number
of queue entries is based on the bandwidth rate.
Note
When you specify the
queue-limit
command, the router
uses tail drop to drop packets.
Step 5
Router(config-pmap-c)#
random-detect
(Optional) Enables WRED.
Note
When you specify the
random-detect
command, the
policy map uses WRED to drop packets, not tail drop. If
you configure a class to use WRED, you must ensure that
WRED is not configured on the interface to which you
intend to attach the service policy.
Step 6
Router(config-pmap-c)#
random-detect
exponential-weighting-constant
exponent
or
Router(config-pmap-c)#
random-detect
precedence
precedence min-threshold
max-threshold mark-prob-denominator
Configures the exponential weight factor used in calculating the
average queue length.
exponent
is a number from 1 to 16 used in the average queue size
calculation.
Configures WRED parameters for packets with a specific IP
precedence. Repeat this command for each precedence.
precedence
is the IP precedence number. Valid values are from 0
to 7.
min-threshold
is the minimum average queue length, expressed in
number of packets. Valid values are from 1 to 4096. When the
average queue length reaches the minimum threshold, WRED
randomly drops some packets with the specified IP precedence.
max-threshold
is the maximum average queue length, expressed
in number of packets. Valid values are from the value of the
min-threshold to 4096. When the average queue length exceeds
the maximum threshold, WRED drops all packets with the
specified IP precedence.
mark-prob-denominator
is the denominator for the fraction of
packets dropped when the average queue depth is at the maximum
threshold. For example, if the denominator is 512, 1 out of every
512 packets is dropped when the average queue is at the maximum
threshold. Valid values are from 1 to 65536. The default is 10 (1
out of every 10 packets is dropped at the maximum threshold).
Command
Purpose