Configuring Queue Weights

After a minimum bandwidth guarantee is met by the traffic on a queue, NetVisor OS supports per-queue scheduling weights for the remaining bandwidth. No user intervention is needed by default, as NetVisor OS automatically associates scheduling weights to port queues in accordance with the minimum bandwidth guarantees. 

When you configure a minimum bandwidth guarantee without specifying a weight value, the weight for the port queue is set on a scale between 1 and 100 when auto-configuration is enabled. (In other words, instead of a binary value, a decimal one is used in the queue weights, which represents a non-zero percentage.)

If auto-configuration of weights is disabled, you can manually assign the desired weight values to the queues. When you configure queue weights manually, the bandwidth that remains after meeting the minimum bandwidth guarantee is proportionally divided among the queues in accordance with the assigned weights.

To enable or disable automatic weight assignment for port queues, use the command:

CLI (network-admin@switch) > system-settings-modify cosq-weight-auto|no-cosq-weight-auto

CLI (network-admin@switch) > system-settings-show format cosq-weight-auto,

cosq-weight-auto: off

CLI (network-admin@switch) > system-settings-modify cosq-weight-auto 

CLI (network-admin@switch) > port-cos-bw-show

switch cos port  min-bw-guarantee max-bw-limit weight 

------ --- ----- ---------------- ------------ ------ 

switch 0   1-128 0%               100%         1

switch 1   1-128 0%               100%         1

switch 2   1-128 20%              100%         20

switch 3   1-128 0%               100%         1

switch 4   1-128 40%              100%         40

switch 5   1-128 0%               100%         1

switch 6   1-128 0%               100%         1

switch 7   1-128 0%               100%         1

Note: If you enable auto-configuration of queue weights, you cannot change the weights using the port-cos-bw-modify command thereafter. You can still use the command to enable the strict priority queue (see below).

Note: When you enable auto-configuration, the weights for all the queues that do not have the minimum bandwidth configured are set to the default value of 1 (which is the minimum possible value, since zero is not allowed).

You can disable the auto-configuration function and then use the port-cos-bw-modify command to change the port queue weights:

CLI (network-admin@switch) > port-cos-bw-modify 


Modify port CoS bandwidth settings.

cos integer

Specify the CoS priority between 0 and 9. Note: queue 8 and 9 are platform specific.

port port-list

Specify the physical port(s).

min-bw-guarantee min-bw-guarantee-string

Specify the minimum bandwidth as a percentage.

max-bw-limit max-bw-limit-string

Specify the maximum bandwidth as a percentage.

weight priority|no-priority

Specify to enable or disable weight scheduling after the bandwidth guarantee is met.

For example:

CLI (network-admin@switch) > port-cos-bw-modify cos 5 port 10 weight 64