Administrator Guide

NOTE: In addition to the specified pause-threshold value, pause frames are
sent only when the buffer usage exceeds some percentage of the shared
buffer.
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 stopping the transmission of pause frames.
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
size Weightage of the priorities on the shared buffer size in the system. Enter a number in the
range of 0 to 9. The default shared threshold weight is 10.
Command Modes DCB-BUFFER-THRESHOLD mode
Command History
This guide is platform-specific. For command information about other platforms, see the relevant Dell EMC
Networking OS Command Line Reference Guide.
Version Description
9.11(2.0P0) Default values of buffer threshold profile parameters are changed for the Z9100-ON and
S6100-ON.
9.10(0.1) Introduced on the S6010-ON and S4048T-ON.
9.10(0.0) Introduced on the S6100.
9.8(1.0) Introduced on the Z9100–ON.
9.8(0.0) Introduced on the S3048-ON and S4048-ON.
9.7(0.0) Introduced on the S6000-ON.
9.3(0.0) Introduced on the S4810, S4820T, and S6000 platforms.
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
DellEMC(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.
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
Data Center Bridging (DCB) 483