IBM 12.1(22)EA6 - Manual (Page 417)

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Cisco Systems Intelligent Gigabit Ethernet Switch Modules for the IBM BladeCenter, Software Configuration Guide
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Chapter 23 Configuring QoS
Configuring Auto-QoS
Configuring Auto-QoS
You can use the auto-QoS feature to simplify the deployment of existing QoS features. Auto-QoS makes
assumptions about the network design, and as a result, the switch can prioritize different traffic flows
and appropriately use the egress queues instead of using the default QoS behavior (the switch offers
best-effort service to each packet regardless of the packet contents or size and sends it from a single
queue).
When you enable auto-QoS, it automatically classifies traffic based on the traffic type and ingress packet
label. The switch uses the resulting classification to choose the appropriate egress queue.
You use auto-QoS commands to identify ports connected to Cisco IP Phones. You also use the
commands to identify ports that receive trusted traffic through an uplink. Auto-QoS then performs these
functions:
• Detects the presence or absence of IP phones
• Configures QoS classification
• Configures egress queues
These sections describe how to configure auto-QoS on your switch:
• Generated Auto-QoS Configuration, page 23-9
• Effects of Auto-QoS on the Configuration, page 23-11
• Configuration Guidelines, page 23-11
• Enabling Auto-QoS for VoIP, page 23-12
Generated Auto-QoS Configuration
When auto-QoS is enabled, it uses the ingress packet label to classify traffic and to configure the egress
queues as described in
Table 23-2 .
Table 23-2 Traffic Types, Packet Labels, and Egress Queues
VoIP 1 Data
Traffic
1. VoIP = voice over IP
VoIP Control
Traffic Routing Protocol
Traffic STP BPDU 2
Traffic
2. BPDU = bridge protocol data unit
Real-Time
Video Traffic
All Other Traffic
DSCP 46 24, 26 48 56 34 –
CoS 5 3 6 7 4
CoS-to-Queue
Map 5 3, 6, 7 4 2 0, 1
Egress Queue 1% WRR
(queue 4) 70% WRR (queue 3) 20% WRR
(queue 2) 20% WRR
(queue 2) 10% WRR
(queue 1)