Quality of Service: Managing Bandwidth More Effectively
Advanced Classifier-Based QoS
N o t e
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Classifier-Based QoS Model
Classifier-based QoS configuration consists of the following general steps:
1.
Classify the traffic that you want to manage by configuring a class.
2.
Configure a QoS policy in which you specify the QoS actions to execute
on each class of traffic.
3.
Assign the QoS policy to a port or VLAN (inbound only) interface.
Classifier-based QoS operation supports all globally-configured packet classi-
fication criteria (except for Source-port and Layer-3 protocol) and traffic
marking functions, and provides additional QoS actions on a per-port and per-
VLAN basis.
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Classifier-based match criteria on inbound IPv4/IPv6 traffic include:
•
IP source address (IPv4 and IPv6)
•
IP destination address (IPv4 and IPv6)
•
IP protocol (such as ICMP or SNMP)
•
Layer 3 IP precedence bits
•
Layer 3 DSCP codepoint
•
Layer 4 TCP/UDP application port (including TCP flags)
•
VLAN ID
Classifier-based QoS policy actions on matching IPv4/IPv6 packets are as
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follows:
•
Setting the Layer 2 802.1p priority value (class of service) in VLAN-
tagged and untagged packet headers
•
Setting the Layer 3 IP precedence bits
•
Setting the Layer 3 Differentiated Services Codepoint (DSCP) bits
•
Rate-limiting inbound traffic on port and VLAN interfaces
Classifier-Based QoS Configuration Procedure
To use the classifier-based model to configure a QoS policy and apply it to a
selected class of traffic on a port or VLAN interface, follow these steps:
1.
Evaluate the types of traffic in your network and identify the traffic types
that you want to prioritize or rate-limit.