Configuring Modular Qos Congestion Avoidance - Cisco ASR 9000 Series Configuration Manual

Configuring Modular QoS Congestion Avoidance

Congestion avoidance techniques monitor traffic flow in an effort to anticipate and avoid congestion at
common network bottlenecks. Avoidance techniques are implemented before congestion occurs as compared
with congestion management techniques that control congestion after it has occurred.
Congestion avoidance is achieved through packet dropping. Cisco IOS XR software supports these quality
of service (QoS) congestion avoidance techniques that drop packets:
• Random early detection (RED)
• Weighted random early detection (WRED)
• Tail drop
The module describes the concepts and tasks related to these congestion avoidance techniques.
Line Card, SIP, and SPA Support
Feature
Random Early Detection
Weighted Random Early Detection
Tail Drop
Feature History for Configuring Modular QoS Congestion Avoidance on Cisco ASR 9000 Series Routers
Release
Release 3.7.2
Release 3.9.0
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide, Release 6.1.x
C H A P T E R
ASR 9000 Ethernet Line Cards
yes
yes
yes
Modification
The Congestion Avoidance feature was introduced on ASR 9000 Ethernet
Line Cards.
The Random Early Detection, Weighted Random Early Detection, and Tail
Drop features were introduced on ASR 9000 Ethernet Line Cards.
The Random Early Detection, Weighted Random Early Detection, and Tail
Drop features were supported on the SIP 700 for the ASR 9000.
4
SIP 700 for the ASR 9000
yes
yes
yes
39