Generated Auto-Qos Configuration - Cisco Catalyst 3550 series Software Configuration Manual

Configuring Auto-QoS

Generated Auto-QoS Configuration

By default, auto-QoS is disabled on all interfaces.
When auto-QoS is enabled, it uses the ingress packet label to categorize traffic and to configure the
egress queues as shown in
Table 29-1 Traffic Types, Ingress Packet Labels, Assigned Packet Labels, and Egress Queues
Ingress DSCP
Ingress CoS
DiffServ
Assigned DSCP 46
Assigned CoS
CoS-to-Queue
Map
Egress Queue
1. BPDU = bridge protocol data unit.
Table 29-2
Table 29-2 Auto-QoS Configuration for the Egress Queues
Egress Queue
Expedite
80% WRR
20% WRR
When you enable the auto-QoS feature on the first interface, these automatic actions occur:
•
•
•
Catalyst 3550 Multilayer Switch Software Configuration Guide
29-18
Table
VoIP Data
Traffic Only
From Cisco IP
Phones
46
5
EF
5
5
Expedite
queue
shows the generated auto-QoS configuration for the egress queues.
Queue CoS-to-Queue
Number Map
4 5
3 3, 6, 7
1 0, 1, 2, 4
QoS is globally enabled (mls qos global configuration command).
When you enter the auto qos voip trust interface configuration command, the ingress classification
on the interface is set to trust the QoS label received in the packet, and the egress queues on the
interface are reconfigured (see
When you enter the auto qos voip cisco-phone interface configuration command, the trusted
boundary feature is enabled. It uses the Cisco Discovery Protocol (CDP) to detect the presence or
absence of a Cisco IP phone. When a Cisco IP phone is detected, the ingress classification on the
interface is set to trust the QoS label received in the packet. When a Cisco IP phone is absent, the
ingress classification is set to not trust the QoS label in the packet. The egress queues on the
interface are also reconfigured (see
29-1.
VoIP Control
Traffic Only
From Cisco IP Routing Protocol
Phones Traffic
26 –
3 6
AF31 –
26 48
3 6
3, 6, 7
80% WRR
Queue
Weight
–
80%
20%
Table 29-2).
Table 29-2).
Chapter 29
1
STP BPDU
Traffic
–
7
–
56
7
Queue Size for Queue Size (in
Gigabit-Capable packets) for 10/100
Ports Ethernet Ports
– 26
20% 65
80% 170
Configuring QoS
All Other
Traffic
–
–
–
0
0
0, 1, 2, 4
20% WRR
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