Dell EMC Configuration Guide for the S4048T–ON System 9.14.2.4

Configuring the Dynamic Buffer Method

Priority-based flow control using dynamic buffer spaces is supported on the switch.

1. Enable the DCB application. By default, DCB is enabled and link-level flow control is disabled on all interfaces.
   CONFIGURATION mode
   dcb enable
2. Configure the shared PFC buffer size and the total buffer size. A maximum of 4 lossless queues are supported.
   CONFIGURATION mode
   dcb pfc-shared-buffer-size value
   dcb pfc-total-buffer-size value
   The buffer size range is from 0 to 3399. Default is 3088.
3. Configure the number of PFC queues.
   CONFIGURATION mode
   dcb enable pfc-queues pfc-queues

   The number of ports supported based on lossless queues configured depends on the buffer. The default number of PFC queues in the system is two.

   For each priority, you can specify the shared buffer threshold limit, the ingress buffer size, buffer limit for pausing the acceptance of packets, and the buffer offset limit for resuming the acceptance of received packets.

4. Configure the profile name for the DCB buffer threshold
   CONFIGURATION mode
   dcb-buffer-threshold dcb-buffer-threshold
5. 
   
   DCB-BUFFER-THRESHOLD mode
   priority 0 buffer-size 52 pause-threshold 16 resume-offset 10 shared-threshold-weight 7
6. Assign the DCB policy to the DCB buffer threshold profile on stack ports.
   CONFIGURATION mode
   DellEMC(conf)# dcb-policy buffer-threshold stack-unit all stack-ports all dcb-policy-name
7. Assign the DCB policy to the DCB buffer threshold profile on interfaces. This setting takes precedence over the default buffer-threshold setting.
   INTERFACE mode
   dcb-policy buffer-threshold dcb-buffer-threshold
8. Configuring Global total buffer size on stack ports.
   CONFIGURATION mode
   dcb pfc-total-buffer-size buffer-size stack-unit all port-set {port-pipe |all}
   Port-set number range is from 0 to 3.