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Dell PowerEdge FN I/O Module Command Line Reference Guide 9.10(0.0)

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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 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
size	Weightage of the priorities on the shared buffer size in the system. Enter a number in the range from 0 to 9. The default shared threshold weight is 10.

Default

The default size of the ingress buffer is 45 KB. The default buffer limit at which the port sends the pause to peer and recommences the sending of packets to the peer is 10 KB. The default threshold weight of the shared buffer space is 10.

Command Modes

DCB-BUFFER-THRESHOLD mode

Supported Modes

Full–Switch

Command History

Version	Description
9.9(0.0)	Introduced on the FN IOM.
9.3(0.0)	Introduced on the MXL platform.

Usage Information

You must apply this buffer policy at the interface level for the attributes to be applicable in conjunction with the DCB input policy.

For each QoS policy buffer, 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 set up both the administrative and peer-related PFC priorities. For example, you can configure the intended buffer configuration for all 8 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)# qos-policy-buffer test

Dell (conf-qos-policy-buffer)#queue 0 pause no-drop buffer-size 128000 pause-threshold 103360 resume-threshold 83520

Dell(conf-qos-policy-buffer)# queue 4 pause no-drop buffer-size 128000 pause-threshold 103360 resume-threshold 83520