Users Guide

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
Dell(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. This utility is supported on the S4820T .
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.
resume-oset Buer oset limit for resuming in KB
threshold-value Buer oset 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
Buer shared threshold weight
504
Data Center Bridging (DCB)