D-Link DWS-4026 Product Manual - Page 336

D-Link Unified Access System Software User Manual 12/10/09 Field Slot/Port 802.1p Priority Traffic Class Table 212: 802.1p Priority Mapping Description Selects the interface to which the class of service configuration is applied. Displays the 802.1p priority to be mapped. Priority goes from low (0) to high (7). For example, traffic with a priority of 0 is for most data traffic and is sent using "best effort." Traffic with a higher priority, such as 6, might be time-sensitive traffic, such as voice or video. The traffic class is the hardware queue for a port. Higher traffic class values indicate a higher queue position. Before traffic in a lower queue is sent, it must wait for traffic in higher queues to be sent. To change the default priority-to-queue mapping, select a new traffic class value from the drop-down menu. • If you make any changes to the page, click Submit to apply the new values to the system. TRUST MODE CONFIGURATION Use the Trust Mode Configuration page to set the class of service trust mode of an interface. Each port in the switch can be configured to trust one of the packet fields (802.1p or IP DSCP), or to not trust any packet's priority designation (untrusted mode). If the port is set to a trusted mode, it uses a mapping table appropriate for the trusted field being used. This mapping table indicates the CoS queue to which the packet should be forwarded on the appropriate egress port(s). Of course, the trusted field must exist in the packet for the mapping table to be of any use, so there are default actions performed when this is not the case. These actions involve directing the packet to a specific CoS level configured for the ingress port as a whole, based on the existing port default priority as mapped to a traffic class by the current 802.1p mapping table. Alternatively, when a port is configured as untrusted, it does not trust any incoming packet priority designation and uses the port default priority value instead. All packets arriving at the ingress of an untrusted port are directed to a specific CoS queue on the appropriate egress port(s) in accordance with the configured default priority of the ingress port. This process is also used for cases where a trusted port mapping is unable to be honored, such as when a non-IP packet arrives at a port configured to trust the IP precedence or IP DSCP value. To display the Trust Mode Configuration page, click LAN > QoS > Class of Service > Trust Mode Configuration in the navigation menu. Page 336 Configuring Class of Service Document 34CSFP6XXUWS-SWUM100-D7