Dell Force10 S4820T S4820T Configuration Guide - Page 295

Task Command Command Mode Set PFC buffering on the DCB stack unit. dcb stack-unit all pfc-buffering pfc-ports 64 pfc-queues 2 CONFIGURATION Note: Save the configuration and reboot the system to save the pfc buffering configuration changes. FTOS Behavior: DCB is not supported if you enable link-level flow control on one or more interfaces (refer to Ethernet Pause Frames on page 470). 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: Using the service-class dynamic dot1p command in INTERFACE configuration mode, you can honor dot1p priorities in ingress traffic at the port or global switch level (refer to Default dot1p to Queue Mapping). • Layer 2 class maps: You can use dot1p priorities to classify traffic in a class map and apply a service policy to an ingress port to map traffic to egress queues (refer to Policy-based QoS Configurations). Note: Dell Force10 does not recommend mapping all ingress traffic to a single queue when using PFC Important: of two 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 13-1 and the maximum number of two lossless queues supported on a port (refer to Configuring Lossless Queues). Although FTOS allows you to change the default dot1p priority-queue assignments (refer to Set dot1p Priorities for Incoming Traffic), 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. Data Center Bridging (DCB) | 295