Dell PowerConnect FCS624S Configuration Guide - Page 635

Classification 17 FIGURE 112 Determining a packet trust level - PowerConnect B-Series FCX devices Packet received on ingress port Does the packet match an ACL that defines a priority? Yes Trust the DSCPCoS-mapping or the DSCP-marking No Does the MAC address match a static entry? Yes Trust the priority of the static MAC entry No Is the packet tagged? Yes Trust the 802.1p CoS value No Does the port have a default priority? Yes Trust the port's default priority No Use the default priority of 0 Once a packet is classified, it is mapped to an internal forwarding queue. There are eight queues designated 0 through 7. The internal forwarding priority maps to one of these eight queues as shown in Table 94 through Table 97. The mapping between the internal priority and the forwarding queue cannot be changed. Table 94 through Table 97 show the default QoS mappings that are used if the trust level for CoS or DSCP is enabled. PowerConnect B-Series FCX Configuration Guide 593 53-1002266-01