Administrator Guide

Policy-Based QoS Congurations
Policy-based QoS congurations consist of the components shown in the following example.
Figure 122. Constructing Policy-Based QoS Congurations
Classify Trac
Class maps dierentiate trac so that you can apply separate quality of service policies to dierent types of trac.
For both class maps, Layer 2 and Layer 3, the system matches packets against match criteria in the order that you congure them.
Creating a Layer 3 Class Map
A Layer 3 class map dierentiates ingress packets based on the DSCP value, IP precedence, VLANs, or characteristics dened in an IP
ACL. You can also use VLAN IDs and VRF IDs to classify the trac using layer 3 class-maps.
You can specify more than one DSCP and IP precedence value, but only one value must match to trigger a positive match for the class
map.
NOTE
: IPv6 and IP-any class maps cannot match on ACLs or VLANs.
Quality of Service (QoS) 817