Enterasys Networks X-Pedition XSR CLI - Manual (Page 489)

Policy-Map Commands
XSR CLI Reference Guide 12-93
random-detect (WRED)
This command configures and enables Weighted Random Early Detect (WRED) for the class.
WRED is a congestion avoidance mechanism that slows traffic by randomly dropping packets
when congestion exists. WRED is useful with protocols like TCP that respond to dropped packets
by decreasing the transmission rate.
To set or change WRED parameters, use the random-detect {dscp | precedence} command.
If no parameter passed to the command, the default is prec‐based WRED.
Syntax
random-detect {dscp-based | prec-based}
Syntax of the “no” Form
The no form of this command disables WRED on an interface:
no random-detect
Mode
Policy‐Map Class configuration: XSR(config-pmap-c-<xx>)#
Default
Prec‐based
Example
The following example enables WRED as DSCP‐based with the default values for parameters:
XSR(config)#policy-map DSCP
XSR(config-pmap)#class A
XSR(config-pmap-c)#random-detect dscp-based
random-detect dscp
This command changes the Weighted Random Early Detect (WRED) minimum and maximum
threshold and maximum drop probability for a DiffServ Code Point (DSCP) value.
This command specifies the DiffServ Code Point (DSCP) value. The DSCP can be a number from 0
to 63, or any of the following keywords: af1, af12 , af13, af21, af22, af23, af31, af32, af33, af41, af42,
af43, cs1, cs2, cs3, cs4, cs5, cs6, cs7, ef or default. Each DSCP value has initial WRED parameters.
Table 12‐1 provides initial parameter settings for each DSCP value. The last row details
parameters for DSCP values not shown in the table.
dscp-based WRED uses DSCP values when calculating drop probability.
prec-based WRED uses IP precedence values when calculating drop probability.
Note: This command must be used in conjunction with the random-detect (interface) command.
Also, random-detect dscp is available only if you specified the dscp-based argument when
using the random-detect (interface) command.