Reference Guide

Data Center Bridging (DCB) | 59

QoS dot1p Traffic Classification and Queue Assignment

DCB supports PFC, ETS, and DCBX to handle converged Ethernet traffic that is assigned to an egress

queue according to the following quality of service (QoS) methods:

• Honor dot1p: dot1p priorities in ingress traffic are used at the port or global switch level.

• Layer 2 class maps: dot1p priorities are used to classify traffic in a class map and apply a service

policy to an ingress port to map traffic to egress queues.

Table 6-1. dot1p Priority-Queue Assignment

Important: of two

Note: Dell Force10 does not recommend mapping all ingress traffic to a single queue when using PFC

and ETS. Ingress traffic classification using the service-class dynamic dot1p command (honor dot1p) is

recommended on all DCB-enabled interfaces. If you use L2 class maps to map dot1p priority traffic to

egress queues, take into account the default dot1p-queue assignments in Table 6-1 and the maximum

number of two lossless queues supported on a port.

Although FTOS allows you to change the default dot1p priority-queue assignments, DCB policies applied

to an interface may become invalid if dot1p-queue mapping is reconfigured. If the configured DCB policy

remains valid, the change in the dot1p-queue assignment is allowed. For DCB ETS enabled interfaces,

traffic destined to queue that is not mapped to any dot1p priority will be dropped.

dot1p Value in Incoming Frame Egress Queue Assignment