Cisco IE 3000 User Manual

32-6
Cisco IE 3000 Switch Software Configuration Guide
OL-13018-01
Chapter 32 Configuring QoS
Understanding QoS
Figure 32-3 Classification Flowchart
Classification Based on QoS ACLs
You can use IP standard, IP extended, or Layer 2 MAC ACLs to define a group of packets with the same
characteristics (class). In the QoS context, the permit and deny actions in the access control entries
(ACEs) have different meanings than with security ACLs:
• If a match with a permit action is encountered (first-match principle), the specified QoS-related
action is taken.
• If a match with a deny action is encountered, the ACL being processed is skipped, and the next ACL
is processed.
• If no match with a permit action is encountered and all the ACEs have been examined, no QoS
processing occurs on the packet, and the switch offers best-effort service to the packet.
• If multiple ACLs are configured on a port, the lookup stops after the packet matches the first ACL
with a permit action, and QoS processing begins.
Note When creating an access list, remember that, by default, the end of the access list contains an implicit
deny statement for everything if it did not find a match before reaching the end.
86835
Ye s
Ye s
No
No
Pass
through Drop
Mark
Get the clasification
result for the packet.
Is a policer configured
for this packet?
Check if the packet is in
profile by querying the policer.
Check out-of-profile action
configured for this policer.
Drop packet.
Modify DSCP according to the
policed-DSCP map. Generate
a new QoS label.
Start
Done

Cisco IE 3000 Specifications

General

Brand	Cisco
Model	IE 3000
Category	Switch
Language	English