Cisco Systems 3750E Manuale Utente
36-23
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02
Chapter 36 Configuring QoS
Configuring Auto-QoS
Generated Auto-QoS Configuration
By default, auto-QoS is disabled on all ports.
When auto-QoS is enabled, it uses the ingress packet label to categorize traffic, to assign packet labels,
and to configure the ingress and egress queues as shown in
and to configure the ingress and egress queues as shown in
shows the generated auto-QoS configuration for the ingress queues.
shows the generated auto-QoS configuration for the egress queues.
When you enable the auto-QoS feature on the first port, these automatic actions occur:
•
QoS is globally enabled (mls qos global configuration command), and other global configuration
commands are added.
commands are added.
•
When you enter the auto qos voip cisco-phone interface configuration command on a port at the
edge of the network that is connected to a Cisco IP Phone, the switch enables the trusted boundary
feature. The switch 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 port is set to
edge of the network that is connected to a Cisco IP Phone, the switch enables the trusted boundary
feature. The switch 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 port is set to
Table 36-2
Traffic Types, Packet Labels, and Queues
VoIP
1
Data
Traffic
1.
VoIP = voice over IP
VoIP Control
Traffic
Traffic
Routing Protocol
Traffic
Traffic
STP BPDU
Traffic
Traffic
Real-Time
Video Traffic
Video Traffic
All Other Traffic
DSCP
46
24, 26
48
56
34
–
CoS
5
3
6
7
4
–
CoS-to-Ingress
Queue Map
Queue Map
2, 3, 4, 5, 6, 7 (queue 2)
0, 1 (queue 1)
CoS-to-Egress
Queue Map
Queue Map
5 (queue 1)
3, 6, 7 (queue 2)
4 (queue 3)
2 (queue 3)
0, 1
(queue 4)
(queue 4)
Table 36-3
Auto-QoS Configuration for the Ingress Queues
Ingress Queue
Queue Number
CoS-to-Queue Map
Queue Weight
(Bandwidth)
(Bandwidth)
Queue (Buffer)
Size
Size
SRR shared
1
0, 1
81 percent
67 percent
Priority
2
2, 3, 4, 5, 6, 7
19 percent
33 percent
Table 36-4
Auto-QoS Configuration for the Egress Queues
Egress Queue
Queue Number
CoS-to-Queue Map
Queue Weight
(Bandwidth)
(Bandwidth)
Queue (Buffer) Size
for Gigabit-Capable
Ports
for Gigabit-Capable
Ports
Queue (Buffer)
Size for 10/100
Ethernet Ports
Size for 10/100
Ethernet Ports
Priority (shaped)
1
5
10 percent
16 percent
10 percent
SRR shared
2
3, 6, 7
10 percent
6 percent
10 percent
SRR shared
3
2, 4
60 percent
17 percent
26 percent
SRR shared
4
0, 1
20 percent
61 percent
54 percent