set dcb cn congestion-point

Use this command to modify congestion point queue settings.

Syntax

Parameters

Defaults

• The set point value default value is 26000 octets.
• The weight value default is 1.

Mode

All command modes.

Usage

This command provides for the modification of a subset of congestion queue parameters. A congestion queue is identified by the port and CNPV which it serves. A congestion queue on a given port may serve multiple CNPVs if multiple priorities are mapped to the same queue. A queue profile which currently provides for the configuration of the minimum sample option can also be associated with the congestion point configuration using the qp-index option.

The congestion point index value is assigned by the firmware when the congestion point entry is created. The congestion point index value is one greater than the lowest CNPV served by the congestion point. This is because the CNPV values are 0 based and congestion point index is 1‘s based.

The set point for the queue managed by the congestion point is a target value for the number of octets in the congestion point queue. CNM PDUs are transmitted to the sources of frames queued in this congestion point's queue in order to keep the total number of octets stored in the queue at the set point value.

W is the weight to be given to the change in queue length when calculating a measure of transmit queue congestion known as quantitized feedback (Fb) as defined in the IEEE 802.1Q-2011 standard. The weight option is an integer value from which W is derived. W is equal to two to the power of the weight value specified here. Thus, if weight equals a -1, W = 1/2. This value can be between the values specified by Min Weight and Max Weight for this device as displayed by show dcb cn q-profile. See the IEEE 802.1Q-2011 standard for a detailed discussion for W, weight, and Fb.

The queue profile index option allows for the association of a congestion notification queue profile with the ports assigned to this congestion notification configuration. The queue profile is configured using set dcb cn q-profile.