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Cisco Systems IntelligentGigabit Ethernet Switch Modules for the IBMBladeCenter, Software Configuration Guide
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Chapter23 Co nfiguring QoS
Configuring Standard QoS
Configuring Standard QoS
Before configuring standard QoS, you must have a thorough understanding of these items:
•The types of applications used and the traffic patterns on your network.
•Traffic characteristics and needs of your network. Is the traffic bursty? Do you need to reserve
bandwidth for voice and video streams?
•Bandwidth requirements and speed of the network.
•Location of congestion points in the network.
This section describes how to configure standard QoS on your switch:
•Default Standard QoS Configuration, page 23-16
•Configuration Guidelines, page 23-16
•Configuring Classification Using Port Trust States, page 23-17
•Configuring a QoS Policy, page 23-23
•Configuring CoS Maps, page 23-31
•Configuring the Egress Queues, page 23-34

Default Standard QoS Configuration

This is the default standard QoS configuration:
•The default port CoS value is 0.
•The CoS value of 0 is assigned to all incoming packets.
•The default port trust state is untrusted.
•No policy maps are configured.
•No policers are configured.
•The default CoS-to-DSCP map is shown in Table23-7.
•The default DSCP-to-CoS map is shown in Table 23-8.
•The default scheduling method for the egress queues is strict priority.
•For default CoS and WRR values, see the “Configuring the Egress Queues” section on page 23-34.
Configuration Guidelines
Before beginning the QoS configuration, you should be aware of this information:
•You must disable the IEEE 802.3x flowcontrol on all ports before enabling QoS on the switch. To
disable it, use the flowcontrol rece ive off and flowcontrol send off interface configuration
commands.
•If you have EtherChannel ports configured on your switch, you must configure QoS classification,
policing, mapping, and queueing on the individual physical por ts that comprise the EtherChannel.
You must decide whether the QoS configuration should match on all ports in the EtherCh annel.
•It is not possible to match IP fragments against configured IP extended ACLs to enforce Qo S. IP
fragments are sent as best-effort traffic. IP fragments are denoted by fields in the IP header.