Administrator Guide

Usage
Information
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. When PFC detects congestion on a queue for a specified priority, it sends a pause frame for the
802.1p priority traffic to the transmitting device.
You can use the priority command to set up both the administrative and peer-related PFC priorities.
For example, you can configure the intended buffer configuration for all eight priorities. If you configure
the number of lossless queues as 4 and if the administrator-configured priorities configured within the
DCB input policy is applied, then the configuration for those priorities are pre-designed. However, if the
peer-provided priorities are applied, although a DCB input policy is present, the peer-provided priorities
become effective for buffer configuration. This method of configuration provides an easy and flexible
technique to accommodate both administratively-configured and peer-configured priorities.
Example
Dell(conf-dcb-buffer-thr)#priority 0 buffer-size 52 pause-threshold 16
resume-offset 10 shared-threshold-weight 7
qos-policy-buffer
Create a QoS policy buffer and enter the configuration mode to configure the no-drop queues, ingress buffer size, buffer limit
for pausing, and buffer offset limit for resuming. .
C9000 Series
Syntax
qos-policy-buffer queue queue-num pause no-drop queue buffer-size size
pause-threshold threshold-value resume-offset threshold-value shared-
threshold-weight size
Parameters
policy-name Name of the QoS policy buffer that is applied to an interface for this setting to be
effective in conjunction with the DCB input policy. 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. This method of configuration enables different peer-provided and
administrative priorities to be set up because the intended queue is directly
configured instead of determining the priority to queue mapping for local and
remote parameters.
queue 0 to queue
7
Specify the queue number to which the QoS policy buffer parameters apply
pause Pause frames to be sent at the specified buffer limit levels and pause packet
settings
no-drop The packets for this queue must not be dropped
value Enter a number in the range of 0 to 7 to denote the priority to be allocated to the
dynamic buffer control mechanism
buffer-size Ingress buffer size
size Size of the ingress buffer in KB. Enter a number in the range of 0 to 7787. The
default is 45 KB.
pause-threshold Buffer limit for pause frames to be sent
threshold-value Buffer limit at which the port sends the pause to peer in KB. Enter a number in the
range of 0 to 7787. The default is 10 KB.
resume-offset Buffer offset limit for resuming in KB
threshold-value Buffer offset limit at which the port resumes the peer in KB. Enter a number in the
range of 1 to 7787. The default is 10 KB.
shared-
threshold-weight
Buffer shared threshold weight
Data Center Bridging (DCB) 561