Users Guide

Version Description
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 buer threshold limit, the ingress buer size, buer limit for pausing
the acceptance of packets, and the buer oset limit for resuming the acceptance of received packets. When PFC
detects congestion on a queue for a specied priority, it sends a pause frame for the 802.1p priority trac 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 congure the intended buer conguration for all eight priorities. If you congure the number of
lossless queues as 4 and if the administrator-congured priorities congured within the DCB input policy is applied,
then the conguration 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 eective for buer conguration. This
method of conguration provides an easy and exible technique to accommodate both administratively-congured
and peer-congured priorities.
Example
DellEMC(conf-dcb-buffer-thr)# priority 0 buffer-size 52 pause-threshold 16
resume-offset 10 shared-threshold-weight 7
qos-policy-buer
Create a QoS policy buer and enter the conguration mode to congure the no-drop queues, ingress buer size, buer limit for pausing,
and buer oset 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 buer that is applied to an interface for this setting to be
eective in conjunction with the DCB input policy. You can specify the shared buer
threshold limit, the ingress buer size, buer limit for pausing the acceptance of packets,
and the buer oset limit for resuming the acceptance of received packets. This method
of conguration enables dierent peer-provided and administrative priorities to be set up
because the intended queue is directly congured 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 buer parameters apply
pause Pause frames to be sent at the specied buer 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
buer control mechanism
buer-size Ingress buer size
size Size of the ingress buer in KB. Enter a number in the range of 0 to 7787. The default is
45 KB.
pause-threshold Buer limit for pause frames to be sent
threshold-value Buer 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.
Data Center Bridging (DCB) 589