Configuring Quality of Service 443
Configuring QoS Global Settings
Quality of Service (QoS) provides the ability to implement QoS and priority queuing within a network.
The Global Settings page contains a field for enabling or disabling QoS. It also contains a field for selecting
the Trust mode. The Trust mode relies on predefined fields within the packet to determine the egress queue.
In addition, the Global Settings page enables defining queues as either Strict Priority (SP) or Weighted
Round Robin (WRR).
To open the Global Settings page, click Quality of Service→ QoS Parameters → Global Settings in the
tree view.
Figure 9-1. Global Settings
The Global Settings page contains the following sections:
• QoS Setti ngs
• Queue Settings
QoS Settings
•
Quality of Service
— Enables or disables managing network traffic using Quality of Service.
•
Trust Mode
— Determines which packet fields are used to classify packets entering the device.
When no rules are defined, the traffic containing the predefined CoS or DSCP packet field is mapped
according to the selected trust mode. Traffic not containing a predefined packet field is mapped to the
best effort queue (q2). The possible Trust Mode field values are:
–
CoS
(802.1p) — The egress queue assignment is determined by the IEEE802.1p VLAN priority
tag (VPT) or by the default VPT assigned to a port. The device default is the IEEE802.1p.
–
DSCP
— The egress queue assignment is determined by the DSCP field.
NOTE: The interface Trust settings overrides the global Trust setting.