Dell PowerConnect 3524 User's Guide - Page 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 Settings • 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. Configuring Quality of Service 443