Cisco ASR 9000 Series Service Configuration Guide

QC-73
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide
OL-23108-02
Configuring Modular QoS Congestion Avoidance
on Cisco ASR 9000 Series Routers
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 the
following 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 History for Configuring Modular QoS Congestion Avoidance on Cisco ASR 9000 Series Routers
Contents
• Prerequisites for Configuring Modular QoS Congestion Avoidance on
Cisco ASR 9000 Series Routers, page 74
Feature ASR 9000 Ethernet Line Cards SIP 700 for the ASR 9000
Random Early Detection yes yes
Weighted Random Early Detection yes yes
Tail Drop yes yes
Release Modification
Release 3.7.2 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.
Release 3.9.0 The Random Early Detection, Weighted Random Early Detection, and Tail
Drop features were supported on the SIP 700 for the ASR 9000.

Cisco ASR 9000 Series Specifications

General

Brand	Cisco
Model	ASR 9000 Series
Category	Network Router
Language	English