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Configuring Quality of Service 441
Configuring Quality of Service
This section provides information for defining and configuring Quality of Service (QoS) parameters.
To open the Quality of Service page, click Quality of Service in the tree view.
This section contians the following topics:
• "Quality of Service (QoS) Overview" on page 441
• "Configuring QoS Global Settings" on page 443
Quality of Service (QoS) Overview
Quality of Service (QoS) provides the ability to implement QoS and priority queuing within a network.
An implementation example that requires QoS includes certain types of traffic such as Voice, Video
and real-time traffic, which can be assigned a high priority queue, while other traffic can be assigned
a lower priority queue. The result is an improved traffic flow for traffic with high demand.
QoS is defined by:
•
Classification
— Specifies which packet fields are matched to specific values. All packets
matching the user-defined specifications are classified together.
•
Action
— Defines traffic management where packets being forwarded are based on packet
information, and packet field values such as VLAN priority tag (VPT) and DSCP (DiffServ
Code Point).
VPT Classification Information
VLAN Priority Tags are used to classify the packets by mapping packets to one of the egress queues.
VLAN Priority Tag to queue assignments are user-definable. The table below details the VPT to
queue default settings:
Table 9-1. CoS to Queue Mapping Table Default values
CoS Value Forwarding Queue Values
0q2
1 q1 (Lowest Priority)
2 q1 (Lowest Priority)
3q2
4q3