Currently, Netvisor OS allows a vFlow to mark or re-mark matched packets with a DSCP value on egress. As a result, Netvisor OS does not prioritize any of the traffic in terms of the egress port CoS queue selected for transmit. Another feature, Enabling DSCP to Priority and CoS Mappings introduces the ability to create DSCP QoS maps and apply to ports, but the maps apply to ingress packets. This feature introduces the ability prioritize traffic based on the remarked DSCP value in a vFlow
Netvisor OS creates named DSCP maps as independent objects, and applies the maps to ingress ports for prioritization of packets based on the DSCP markings. In this feature, you can apply the same maps in a vFlow. QoS maps can be applied to ports, but not to Flow Processor entries corresponding to vFlows. This implementation does the prioritization explicitly, since flows can be configured with CoSQ values. The implementation has the following features:
Verify the DSCP map named in the vFlow exists.
Determine the priority and CoS for the DSCP value assigned to the vFlow.
Apply this CoS value to the Flow Processor entry in hardware.
Reconfigure CoS in the flow when the vFlow DSCP setting changes.
Prevent deleting a DSCP map in use by a vFlow.
Update the CoS setting of vFlows using the DSCP map when the DSCP map priority settings are updated.
You can specify the name of a DSCP map in the vflow-create command:
dscp-map dscp-map name | none
Specify the DSCP map to apply on the flow. Please reapply if map priorities are updated.
The vflow-create and vflow-modify commands support a configurable burst-size parameter. The requirement of a flow-class for attaching a meter by configuring the bw-max parameter to a vFlow is removed.
This feature is useful because you can now specify different burst-sizes for different types of metered traffic. For example, you can configure higher burst levels for a metered application that may produce bursty traffic patterns when you click on it, such as a media-rich Web page link.
This feature defaults to burst-size auto, which auto-calculates the burst size based on the maximum bandwidth settings for the vFlow. You can configure a burst-size number between 256B through 128MB.
CLI network-admin@Leaf1>vflow-create name name-string scope local|fabric in-port port-list bw-max bw-max-number burst-size number
For example, to create a vFlow with a burst size of 12 MB, use the following syntax:
CLI network-admin@Leaf1>vflow-create name flow1 scope local in-port 12 bw-max 5G burst-size 12M