Random Early Detection Feature; Weighted Random Early Detection Feature; Queue-Limit Command; Cisco Ios Release: Release 12.0(17)Sl - Cisco 10000 Series Configuration Manual

QoS Features, Commands, and Changes
Cisco IOS Release: Release 12.2(31)SB2
Description: This feature was introduced on the PRE3.

Random Early Detection Feature

Cisco IOS Release: 12.0(17)SL
Description: The random early detection (RED) feature was introduced on the PRE1 to enable the
configuration of a packet drop policy. RED is a mechanism that is used to control congestion by
randomly discarding packets before a queue reaches its queue limit.
Cisco IOS Release: Release 12.0(22)S
Description: This feature was enhanced to include RED based on a differentiated services code point
(DSCP). For the PRE1, DSCP-based RED supports one default drop profile per class, three assured
forwarding (AF) drop profiles per class, and four non-AF drop profiles per policy map.

Cisco IOS Release: Release 12.0(25)SX

Description: This feature was enhanced to allow you to simultaneously configure a packet drop policy
for a class queue (using the random-detect command) and the size of the class queue (using the

queue-limit command).

Cisco IOS Release: Release 12.2(16)BX

Description: This feature was introduced on the PRE2.
Cisco IOS Release: Release 12.2(28)SB
Description: This feature was integrated in Cisco IOS Release 12.2(28)SB.
Cisco IOS Release: Release 12.2(31)SB2
Description: This feature was introduced on the PRE3.

Weighted Random Early Detection Feature

Cisco IOS Release: Release 12.0(17)SL

Description: The weighted random early detection (WRED) feature was introduced on the PRE1 to
provide preferential handling of higher priority packets. WRED allows drop policies based on a
differentiated services code point (DSCP) and IP precedence levels.
Cisco IOS Release: Release 12.0(22)S
Description: This feature was enhanced to include WRED based on a differentiated services code point
(DSCP).
Cisco IOS Release: Release 12.0(25)SX
Description: This feature was enhanced to allow you to simultaneously configure a packet drop policy
for a class queue (using the random-detect command) and the size of the class queue (using the
queue-limit command).
Cisco 10000 Series Router Quality of Service Configuration Guide
1-24
Chapter 1 Quality of Service Overview
OL-7433-09