The qos car command configures QoS CAR parameters.
The undo qos car command deletes the configured QoS CAR parameters.
By default, no QoS CAR parameters are configured in an SSID profile.
qos car inbound cir cir-value [ cbs cbs-value [ pbs pbs-value ] | pir pir-value [ cbs cbs-value pbs pbs-value ] ]
undo qos car inbound
Parameter |
Description |
Value |
|---|---|---|
inbound |
Applies a QoS CAR profile to the inbound direction of an interface. |
- |
cir cir-value |
Specifies the committed information rate (CIR), which is the average rate of traffic that can pass through. |
The value is an integer that ranges from 64 to 4294967295, in kbit/s. |
pir pir-value |
Specifies the peak information rate (PIR), which is the maximum rate of traffic that can pass through. |
The value is an integer that ranges from 64 to 4294967295, in kbit/s. The PIR value must be greater than or equal to the CIR value. |
cbs cbs-value |
Specifies the committed burst size (CBS), which is the average volume of burst traffic that can pass through an interface. |
The value is an integer that ranges from 1500 to 4294967295, in bytes. By default:
|
pbs pbs-value |
Specifies the peak burst size (PBS), which is the maximum volume of burst traffic that can pass through an interface. |
The value is an integer that ranges from 1500 to 4294967295, in bytes. By default, if the PIR is set, the PBS is 125 times the PIR. If the value 125 times the PIR exceeds the maximum value (4294967295) of the PBS, 4294967295 is used. |
Usage Scenario
Traffic policing discards excess traffic to limit incoming and outgoing traffic within a proper range and to protect network resources.
When traffic is transmitted from a high-speed link to a low-speed link, the inbound interface of the low-speed link is prone to severe data loss. The data traffic rate needs to be limited. To solve this problem, configure traffic policing for outgoing traffic on the interface of the high-speed link. The interface then discards the packets whose rate exceeds the traffic policing rate, limiting the outgoing traffic rate in a proper range. You can also configure traffic policing for incoming traffic on the interface of the low-speed link. The interface then discards the received packets whose rate exceeds the traffic policing rate.
QoS CAR parameters can be configured in an SSID profile to implement traffic policing on user traffic on all VAPs to which the user profile is applied. These VAPs share a token bucket, and more VAPs indicate fewer network resources that each VAP can occupy.
Precautions
QoS CAR parameters configured in an SSID profile are valid only when the service data forwarding mode is set to tunnel forwarding.
When the traffic policing rate is greater than the maximum rate of an interface, traffic policing does not take effect on the interface. Set the value of cir-value smaller than the rate of the interface.
When the CBS value is smaller than the number of bytes in a packet, packets of this type are discarded.
To ensure that the device correctly identifies packet colors, you are advised to set the PBS value greater than the CBS value.
When a user is configured as a VIP user, the QoS CAR configured in the SSID profile does not take effect.