Benefits Of Cisco Asr 9000 Series Routers Qos Features; Qos Techniques On Cisco Asr 9000 Series Routers - Cisco ASR 9000 Series Service Configuration Manual

Information About Modular Quality of Service on Cisco ASR 9000 Series Routers
•

Benefits of Cisco ASR 9000 Series Routers 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
the following benefits:
•
•
•

QoS Techniques on Cisco ASR 9000 Series Routers

QoS on Cisco IOS XR software relies on the following techniques to provide for end-to-end QoS
delivery across a heterogeneous network:
•
•
•
Before implementing the QoS features for these techniques, you should identify and evaluate the traffic
characteristics of your network because not all techniques are appropriate for your network environment.
Packet Classification and Marking
Packet classification and marking techniques identify the traffic flow, and provide the capability to
partition network traffic into multiple priority levels or classes of service. After classification is
complete, any other QoS actions can be performed.
Identification of a traffic flow can be performed by using several methods within a single router, such as
access control lists (ACLs), protocol match, IP precedence, IP differentiated service code point (DSCP),
MPLS EXP bit, or Class of Service (CoS).
Marking of a traffic flow is performed by:
•
•
•
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide
QC-2
Additional Cisco IOS XR QoS Supported Features, page QC-5
Control over resources. You have control over which resources (bandwidth, equipment, wide-area
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.
Tailored services. If you are an Internet Service Provider (ISP), the control and visibility provided
by QoS enables you to offer carefully tailored grades of service differentiation to your customers.
Coexistence of mission-critical applications. Cisco IOS XR QoS features make certain of the
following conditions:
That your WAN is used efficiently by mission-critical applications that are most important to
–
your business.
That bandwidth and minimum delays required by time-sensitive multimedia and voice
–
applications are available.
That other applications using the link get their fair service without interfering with
–
mission-critical traffic.
Packet classification and marking
Congestion management
Congestion avoidance
Setting IP Precedence or DSCP bits in the IP Type of Service (ToS) byte.
Setting CoS bits in the Layer 2 headers.
Setting EXP bits within the imposed or the topmost Multiprotocol Label Switching (MPLS) label.
Modular QoS Overview on Cisco ASR 9000 Series Routers
OL-23108-02