Configuring Global Settings

The Global Settings page contains information for enabling Trust on the switch. Packets entering a QoS domain are classified at the edge of the QoS domain.

To define the Trust configuration:

  1. Click Quality of Service > QoS Advanced Mode > Global Settings. The Global Settings page opens.
  2. Select the Trust Mode while the switch is in Advanced mode. If a packet CoS level and DSCP tag are mapped to separate queues, the Trust mode determines the queue to which the packet is assigned:
    • CoS/802.1p--Traffic is mapped to queues based on the VPT field in the VLAN tag, or based on the per-port default CoS/802.1p value (if there is no VLAN tag on the incoming packet), the actual mapping of the VPT to queue can be configured in the mapping CoS/802.1p to Queue page.
    • DSCP--All IP traffic is mapped to queues based on the DSCP field in the IP header. The actual mapping of the DSCP to queue can be configured in the DSCP to Queue page. If traffic is not IP traffic, it is mapped to the best effort queue.
    • CoS/802.1p-DSCP--Select to use Trust CoS mode for non-IP traffic and Trust DSCP for IP traffic.
    • Select Default Mode Status to enable trust mode for ports for Advanced mode QoS.

    NOTE     Configurations done through default mode status parameters are applied on the interfaces that do not have the policies applied to their interfaces.

  3. Select Override Ingress DSCP to override the original DSCP values in the incoming packets with the new values according to the DSCP Override Table. When Override Ingress DSCP is enabled, the switch will use the new DSCP values for egress queueing. It also replaces the original DSCP values in the packets with the new DSCP values.
  4. NOTE     The frame is mapped to an egress queue using the new, rewritten value, and not by the original DSCP value.

  5. If Override Ingress DSCP was enabled, click DSCP Override Table to reconfigure DSCP. See the DSCP Override Table page for details..