Modular Qos Overview; Information About Modular Quality Of Service Overview; Benefits Of Cisco Ios Xr Qos Features - Cisco ASR 9000 Series Configuration Manual

Modular QoS Overview

Quality of Service (QoS) is the technique of prioritizing traffic flows and providing preferential forwarding
for higher-priority packets. The fundamental reason for implementing QoS in your network is to provide
better service for certain traffic flows. A traffic flow can be defined as a combination of source and destination
addresses, source and destination socket numbers, and the session identifier. A traffic flow can more broadly
be described as a packet moving from an incoming interface that is destined for transmission to an outgoing
interface. The traffic flow must be identified, classified, and prioritized on all routers and passed along the
data forwarding path throughout the network to achieve end-to-end QoS delivery. The terms traffic flow and
packet are used interchangeably throughout this module.
To implement QoS on a network requires the configuration of QoS features that provide better and more
predictable network service by supporting bandwidth allocation, improving loss characteristics, avoiding
and managing network congestion, metering network traffic, or setting traffic flow priorities across the
network.
This module contains overview information about modular QoS features within a service provider network.
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Information About Modular Quality of Service Overview

Before configuring modular QoS on your network, you must understand these concepts:

Benefits of Cisco IOS XR QoS Features

The Cisco IOS XR QoS features enable networks to control and predictably service a variety of networked
applications and traffic types. Implementing Cisco IOS XR QoS in your network promotes these benefits:
• Control over resources. You have control over which resources (bandwidth, equipment, wide-area
Information About Modular Quality of Service Overview, page 3
Where to Go Next, page 7
Additional References, page 7
facilities, and so on) are being used. For example, you can limit bandwidth consumed over a backbone
link by FTP transfers or give priority to an important database access.
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide, Release 6.1.x
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