Mqc; Chapter 31 Configuring Qo; System Classes - Cisco AJ732A - MDS 9134 Fabric Switch Configuration Manual

Information About QoS
S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
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MQC

The Cisco Modular QoS CLI (MQC) provides a standard set of commands for configuring QoS.
You can use MQC to define additional traffic classes and to configure QoS policies for the whole system
and for individual Ethernet interfaces. Configuring a QoS policy with MQC consists of the following
steps:
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System Classes

The system class is a new type of MQC target. A service policy can associate a policy map with a system
class, which enables application of a QoS policy across the whole switch.
Parameters in system classes need to be configured consistently across the switch and the whole network
to ensure that packets in a specific traffic class receive consistent treatment as they are transported across
the network.
To ensure QoS consistency (and for ease of configuration), the switch distributes the system class
parameter values to all its attached network adapters using the DCBX protocol. For additional
information about communication between the switch and adapters, see the
Exchange Protocol" section on page
If service policies are configured at the interface level, the interface-level policy always takes precedence
over system class configuration or defaults.
The following QoS parameters can be specified for a system class:
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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
31-2
QoS for Multicast Traffic, page 31-5
Policy for Fibre Channel Interfaces, page 31-6
QoS for Traffic Directed to the CPU, page 31-6
Define traffic classes using the class-map command.
The class map classifies incoming or outgoing packets based on matching criteria, such as the IEEE
802.1p CoS value. Unicast and multicast packets are classified.
Associate policies or actions with each class of traffic using the policy-map command.
The policy map defines a set of actions to take on the associated traffic class, such as limiting the
bandwidth or dropping packets.
Attach policies to MQC targets using the service-policy command.
An MQC target is an entity (such as an Ethernet interface) that represents a flow of packets. A
service policy associates a policy map with an MQC target, and specifies whether to apply the policy
on incoming or outgoing packets. This enables the configuration of interface-specific QoS policies
such as policing and bandwidth allocation.
Drop
No drop specifies lossless service for the system class. Drop specifies that tail drop is used when a
queue for this system class is full.
MTU
The system class MTU defines the maximum packet size for any packet classified into the system
class. Each system class has a default MTU and the system class MTU is configurable.
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Chapter 31 Configuring QoS
"DCE Bridging Capability
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