Dell PowerSwitch S5212F-ON EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 1334

When you enable priority flow control (PFC) on the ports, all the PFC-enabled queues and priority-groups use the buffers from the lossless pool. You must use the network QoS policy type to configure PFC on the ports. OS10 dedicates a separate buffer pool for CPU traffic. All default reserved buffers for the CPU port queues are from the CPU pool. The remaining buffers are shared across all CPU queues. You can modify the buffer settings of CPU queues. You can configure the size of the CPU pool using the control-plane-buffer-size command. OS10 allows configuration of buffers per priority-group and queue for each port. Buffer-usage accounting happens for ingress packets on ingress pools and egress packets on egress pool. You can configure ingress-packet buffer accounting per priority-group and egress-packet buffer accounting per queue level. Configuration notes Dell EMC PowerSwitch S4200-ON Series: ● Provisioning LLFC is not supported when deep buffer mode is enabled. ● Stop the traffic before applying or modifying the LLFC configuration. Configure ingress buffer By default, all traffic classes map to the default priority group (PG) 7 for ingress buffers. The buffer reservation is based on the default priority group ID 7. All buffers are part of the default pool and all ports share buffers from the default pool. When you configure a network qos policy map, a new priority group is created for which buffers are assigned from the lossless pool. The rest of the traffic classes that are not mapped to any PFC-related PGs, use the default buffer. The reserved buffer size is 9360 bytes for the speed of 10G, 25G, 40G, 50G, and 100G. The supported speed varies for different platforms. Table 86. Maximum buffer size Platforms S4000 Max buffer size 12 MB S6010-ON, S4048-ON 16 MB S4100-ON Series 12 MB S4200-ON Series 6 GB S5200-ON Series 32 MB Z9100-ON 16 MB Z9264F-ON 42 MB The following table lists the values allocated for the default ingress buffers on the S4100-ON series platform. These values may differ for different platforms and speeds. Use the show qos ingress buffers command to view the default ingress buffers on your switch. Table 87. Default ingress buffers on the S4100-ON series platform Speed 10G 25G 40G 50G 100G Reserved buffers 9KB 9KB 9KB 9KB 9KB for PG 7 (default) The following lists the link-level flow control (LLFC) buffer settings for default priority group 7: Table 88. Default setting for LLFC Speed Default reserved buffer 10G 25G 40G 9KB 9KB 18KB Default Xon threshold 36KB 45KB 75KB Default Xoff threshold 9KB 9KB 9KB 50G 18KB 91KB 9KB 100G 36KB 142KB 9KB 1334 Quality of service